2024/09/30 更新

写真a

ナカザワ カズヒロ
中澤 知洋
NAKAZAWA Kazuhiro
所属
素粒子宇宙起源研究所 現象解析研究部門 准教授
大学院担当
大学院理学研究科
職名
准教授
外部リンク

学位 1

  1. 博士(理学) ( 2001年3月   東京大学 ) 

研究キーワード 8

  1. ブラックホール

  2. 人工衛星

  3. X線

  4. 宇宙物理

  5. X線天文学

  6. 銀河団

  7. 硬X線

  8. ガンマ線

研究分野 2

  1. 自然科学一般 / 素粒子、原子核、宇宙線、宇宙物理にする理論

  2. 自然科学一般 / 天文学

現在の研究課題とSDGs 2

  1. 宇宙X線MeVガンマ線観測

  2. 雷雲中での粒子加速とガンマ線放射の研究

経歴 2

  1. 東京大学   大学院理学系研究科物理学専攻   講師

    2007年4月 - 2017年12月

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    国名:日本国

  2. JAXA   宇宙科学研究所   助教

    2001年7月 - 2007年3月

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    国名:日本国

学歴 1

  1. 東京大学   理学系研究科   物理学専攻

    1996年4月 - 2001年3月

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    国名: 日本国

所属学協会 3

  1. 日本地球惑星科学連合

    2019年1月 - 現在

  2. 日本天文学会

  3. 日本物理学会

 

論文 122

  1. Indications of an offset merger in Abell 3667

    Omiya Y., Nakazawa K., Tamura T., Akamatsu H., Matsushita K., Okabe N., Sato K., Fujita Y., Gu L., Simionescu A., Ichinohe Y., Riseley C.J., Akahori T., Ito D., Sakai K., Kurahara K.

    Astronomy and Astrophysics   689 巻   2024年9月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Astronomy and Astrophysics  

    Context. Cluster mergers are the most energetic events, releasing kinetic energies of up to 1064 erg and involving megaparsec(Mpc)-scale shocks in their intra-cluster medium (ICM). In merging clusters, cold fronts are frequently observed, which are characterized by temperature and density jumps while maintaining constant pressure. They, together with the overall morphology of the ICM, provide important information for our understanding of the merging structure, such as velocity, impact parameter, and mass. Aims. Abell 3667 is a nearby (z = 0.056) merging cluster with a prominent cold front and a pair of two bright radio relics. Assuming a head-on merger, the origin of the cold front is often considered to be a remnant of the cluster core stripped by its surrounding ICM. Some authors have proposed an offset merger scenario in which the subcluster core rotates after the first core crossing. This scenario can reproduce features such as the cold front and a pair of radio relics. To distinguish between these scenarios, we reanalyzed the ICM distribution and measured the line-of-sight bulk ICM velocity using the XMM-Newton PN data. Methods. We created an unsharp masked image to identify ICM features, and analyzed X-ray spectra to explore the ICM thermodynamical state. Applying the new XMM-Newton European Imaging Camera (EPIC)- PN calibration technique using background emission lines, the line-of-sight bulk ICM velocities were also measured. Results. In the unsharp masked image, we identify several ICM features, some of which we detect for the first time. We confirm the cold front and note an enhanced region extending from the cold front to the west (named "CF-W tail"). There is an enhancement of the X-ray surface brightness extending from the first brightest cluster galaxy (BCG) to the cold front, which is named the "BCG-E tail". The notable feature is a "RG1 vortex", which is a clockwise vortex-like enhancement with a radius of about 250 kpc connecting the first BCG to the radio galaxy (RG1). It is particularly enhanced near the north of the 1st BCG, which is named the "BCG-N tail". The thermodynamic maps show that the ICM of the RG1 vortex has a relatively high abundance of 0.5-0.6 solar compared to the surrounding regions. The ICM of the BCG-E tail also has a high abundance and low pseudo-entropy and can be interpreted as a remnant of the cluster core's ICM. Including its arc-like shape, the RG1 vortex supports the idea that the ICM around the cluster center is rotating, which is natural for an offset merger scenario. The results of the line-of-sight bulk ICM velocity measurements show that the ICM around the BCG-N tail is redshifted with a velocity difference of 940 ± 440 km s-1 compared to the optical redshift of the first BCG. We obtain other indications of variations in the line-of-sight velocity of the ICM and discuss these in the context of an offset merger.

    DOI: 10.1051/0004-6361/202449992

    Scopus

  2. Wide-band x-ray observatory for the time domain astronomy era: CHRONOS

    Kazuhiro Nakazawa, Teruaki Enoto, Wataru B. Iwakiri, Megumi Shidatsu, Hiromitsu Takahashi, Takashi Okajima, Manabu Ishida, Hiromasa Suzuku, Hiroya Yamaguchi, Shin Watanabe, Mariko Kimura, Hiroshi Nakajima, Takaaki Tanaka, Hiroyuki Uchida, Yoshihiro Ueda, Takeshi G. Tsuru, Kosuke Namekata, Koji Mori, Masayoshi Nobukawa, Hironori Matsumoto, Hiroki Akamatsu, Taiki Kawamuro, Satoshi Yamada, Yukikatsu Terada, Yoichi Yatsu, Hirofumi Noda

    Space Telescopes and Instrumentation 2024: Ultraviolet to Gamma Ray     頁: 92 - 92   2024年8月

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE  

    DOI: 10.1117/12.3018366

  3. A broadband x-ray imaging spectroscopy in the 2030s: the FORCE mission

    Koji Mori, Takeshi G. Tsuru, Kazuhiro Nakazawa, Yoshihiro Ueda, Shin Watanabe, Takaaki Tanaka, Manabu Ishida, Hironori Matsumoto, Hisamitsu Awaki, Hiroshi Murakami, Masayoshi Nobukawa, Ayaki Takeda, Yasushi Fukazawa, Hiroshi Tsunemi, Tadayuki Takahashi, Ann E. Hornschemeier, Takashi Okajima, William W. Zhang, Brian J. Williams, Tonia Venters, Kristin Madsen, Mihoko Yukita, Hiroki Akamatsu, Aya Bamba, Teruaki Enoto, Yutaka Fujita, Akihiro Furuzawa, Kouichi Hagino, Kosei Ishimura, Masayuki Itoh, Tetsu Kitayama, Shogo B. Kobayashi, Takayoshi Kohmura, Aya Kubota, Misaki Mizumoto, Tsunefumi Mizuno, Hiroshi Nakajima, Kumiko K. Nobukawa, Hirofumi Noda, Hirokazu Odaka, Naomi Ota, Toshiki Sato, Megumi Shidatsu, Hiromasa Suzuki, Hiromitsu Takahashi, Atsushi Tanimoto, Yukikatsu Terada, Yuichi Terashima, Hiroyuki Uchida, Yasunobu Uchiyama, Hiroya Yamaguchi, Yoichi Yatsu

    Space Telescopes and Instrumentation 2022: Ultraviolet to Gamma Ray     2022年8月

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE  

    DOI: 10.1117/12.2628772

  4. The Compton Spectrometer and Imager Project for MeV Astronomy

    Tomsick J.A., Boggs S.E., Zoglauer A., Wulf E., Mitchell L., Phlips B., Sleator C., Brandt T., Shih A., Roberts J., Jean P., von Ballmoos P., Oliveros J.M., Smale A., Kierans C., Hartmann D., Leising M., Ajello M., Burns E., Fryer C., Saint-Hilaire P., Malzac J., Tavecchio F., Fioretti V., Bulgarelli A., Ghirlanda G., Chang H.K., Takahashi T., Nakazawa K., Matsumoto S., Melia T., Siegert T., Lowell A., Lazar H., Beechert J., Gulick H.

    Proceedings of Science   395 巻   2022年3月

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    出版者・発行元:Proceedings of Science  

    The Compton Spectrometer and Imager (COSI) is a 0.2-5 MeV Compton telescope capable of imaging, spectroscopy, and polarimetry of astrophysical sources. Such capabilities are made possible by COSI's germanium cross-strip detectors, which provide high efficiency, high resolution spectroscopy and precise 3D positioning of photon interactions. Science goals for COSI include studies of 0.511 MeV emission from antimatter annihilation in the Galaxy, mapping radioactive elements from nucleosynthesis, determining emission mechanisms and source geometries with polarization, and detecting and localizing multimessenger sources. The instantaneous field of view (FOV) for the germanium detectors is >25% of the sky, and they are surrounded on the sides and bottom by active shields, providing background rejection as well as allowing for detection of gamma-ray bursts or other gamma-ray flares over >50% of the sky. We have completed a Phase A concept study to consider COSI as a Small Explorer (SMEX) satellite mission, and here we discuss the advances COSI-SMEX provides for astrophysics in the MeV bandpass.

    Scopus

  5. Hard x-ray imager onboard Hitomi (ASTRO-H)

    Nakazawa Kazuhiro, Sato Goro, Kokubun Motohide, Enoto Teruaki, Fukazawa Yasushi, Hagino Kouichi, Hayashi Katsuhiro, Kataoka Jun, Katsuta Junichiro, Kobayashi Shogo B., Laurent Philippe, Lebrun Francois, Limousin Olivier, Maier Daniel, Makishima Kazuo, Mizuno Tsunefumi, Mori Kunishiro, Nakamori Takeshi, Nakano Toshio, Noda Hirofumi, Odaka Hirokazu, Ohno Masanori, Ohta Masayuki, Saito Shinya, Sato Rie, Tajima Hiroyasu, Takahashi Hiromitsu, Takahashi Tadayuki, Takeda Shin'ichiro, Tanaka Takaaki, Terada Yukikatsu, Uchiyama Hideki, Uchiyama Yasunobu, Watanabe Shin, Yamaoka Kazutaka, Yatsu Yoichi, Yuasa Takayuki

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   4 巻 ( 2 )   2018年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    The hard x-ray imaging spectroscopy system of "Hitomi" x-ray observatory is composed of two sets of hard x-ray imagers (HXI) coupled with hard x-ray telescopes (HXT). With a 12-m focal length, the system provides fine (10:7 half-power diameter) imaging spectroscopy covering about 5 to 80 keV. The HXI sensor consists of a camera, which is composed of four layers of Si and one layer of CdTe semiconductor imagers, and an active shield composed of nine Bi4Ge3O12 scintillators to provide low background. The two HXIs started observation on March 8 and 14, 2016 and were operational until 26 March. Using a Crab observation, 5 to 80 keV energy coverage and good detection efficiency were confirmed. The detector background level of 1 to 3 × 10-4 counts s?1 keV?1 cm?2 (in detector geometrical area) at 5 to 80 keV was achieved, by cutting the high-background time-intervals, adopting sophisticated energy-dependent imager layer selection, and baffling of the cosmic x-ray background and active-shielding. This level is among the lowest of detectors working in this energy band. By comparing the effective area and the background, it was shown that the HXI had a sensitivity that is same to that of NuSTAR for point sources and 3 to 4 times better for largely extended diffuse sources.

    DOI: 10.1117/1.JATIS.4.2.021410

    Web of Science

    Scopus

  6. X-Raying Neutral Density Disturbances in the Mesosphere and Lower Thermosphere induced by the 2022 Hunga-Tonga Volcano Eruption

    Satoru Katsuda, Hiroyuki Shinagawa, Hitoshi Fujiwara, Hidekatsu Jin, Yasunobu Miyoshi, Yoshizumi Miyoshi, Yuko Motizuki, Motoki Nakajima, Kazuhiro Nakazawa, Kumiko K Nobukawa, Yuichi Otsuka, Atsuki Shinbori, Takuya Sori, Chihiro Tao, Makoto S Tashiro, Yuuki Wada, Takaya Yamawaki

        2024年8月

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  7. Measurement of temperature relaxation in the postshock plasma of the northwestern limb of SN 1006

    Ichihashi, M; Bamba, A; Kato, Y; Katsuda, S; Suzuki, H; Kasuga, T; Odaka, H; Nakazawa, K

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   76 巻 ( 4 ) 頁: 800 - 809   2024年6月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    Heating of charged particles via collisionless shocks, while ubiquitous in the universe, is an intriguing yet puzzling plasma phenomenon. One outstanding question is how electrons and ions approach an equilibrium after they were heated to different immediate-postshock temperatures. In order to fill the significant lack of observational information of the downstream temperature-relaxation process, we observe a thermal-dominant X-ray filament in the northwest of SN 1006 with Chandra. We divide this region into four layers with a thickness of 15́́ or 0.16 pc each, and fit each spectrum by a non-equilibrium ionization collisional plasma model. The electron temperature was found to increase toward downstream from 0.52–0.62 to 0.82–0.95 keV on a length scale of 60́́ (or 0.64 pc). This electron temperature is lower than thermal relaxation processes via Coulomb scattering, requiring some other effects such as plasma mixture due to turbulence and/or projection effects, etc., which we hope will be resolved with future X-ray calorimeter missions such as XRISM and Athena.

    DOI: 10.1093/pasj/psae049

    Web of Science

    Scopus

  8. Discovery of diffuse radio source in Abell 1060

    Kurahara, K; Akahori, T; Oki, A; Omiya, Y; Nakazawa, K

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   76 巻 ( 2 ) 頁: L8 - L13   2024年4月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    Non-Thermal components in the intra-cluster medium (ICM), such as turbulence, magnetic field, and cosmic rays, imprint the past and current energetic activities of jets from active galactic nuclei (AGN) of member galaxies as well as disturbance caused by galaxy cluster mergers. Meter-and centimeter-radio observations of synchrotron radiation allow us to diagnose the nonthermal component. Here we report on our discovery of an unidentified diffuse radio source, named the Flying Fox, near the center of the Abell 1060 field. The Flying Fox has an elongated ring-like structure and a central bar shape, but there is no obvious host galaxy. The average spectral index of the Flying Fox is-1.4, which is steeper than that for radio sources seen at meter wavelengths. We discussed the possibilities of radio lobes, phoenixes, radio halos and relics, and an odd radio circle. In conclusion, the Flying Fox is not clearly explained by known radio sources.

    DOI: 10.1093/pasj/psae011

    Web of Science

    Scopus

  9. On-ground calibration of the X-ray, gamma-ray, and relativistic electron detector onboard TARANIS

    Wada, Y; Laurent, P; Pailot, D; Cojocari, I; Bréelle, E; Colonges, S; Baronick, JP; Lebrun, F; Blelly, PL; Sarria, D; Nakazawa, K; Lindsey-Clark, M

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   10 巻 ( 2 )   2024年4月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    We developed the X-ray, gamma-ray, and relativistic electron detector (XGRE) onboard the Tool for the Analysis of RAdiation from lightNIngs and Sprites (TARANIS) satellite, to investigate high-energy phenomena associated with lightning discharges such as terrestrial gamma-ray flashes and terrestrial electron beams. XGRE consisted of three sensors. Each sensor has one layer of LaBr3 crystals for X-ray/gamma-ray detections and two layers of plastic scintillators for electron and charged-particle discrimination. Since 2018, the flight model of XGRE was developed, and validation and calibration tests, such as a thermal cycle test and a calibration test with the sensors onboard the satellite, were performed before the launch of TARANIS on 17 November 2020. The energy range of the LaBr3 crystals sensitive to X-rays and gamma rays was determined to be 0.04 to 11.6 MeV, 0.08 to 11.0 MeV, and 0.08 to 11.3 MeV for XGRE1, 2, and 3, respectively. The energy resolution at 0.662 MeV (full width at half maximum) was 20.5%, 25.9%, and 28.6%, respectively. The results from the calibration test were then used to validate a simulation model of XGRE and TARANIS. By performing Monte Carlo simulations with the verified model, we calculated effective areas of XGRE to X-rays, gamma rays, electrons, and detector responses to incident photons and electrons coming from various elevation and azimuth angles.

    DOI: 10.1117/1.JATIS.10.2.026005

    Web of Science

    Scopus

  10. XRISM衛星アーカイブに向けた地上高次データ処理の開発

    寺田 幸功, 田代 信, 高橋 弘充, 信川 正順, 水野 恒史, 宇野 伸一郎, 久保田 あや, 中澤 知洋, 渡辺 伸, 飯塚 亮, 佐藤 理江, 林 克洋, 米山 友景, 吉田 鉄生, 金丸 善朗, 小川 翔司, BALUTA Chris, 海老沢 研, 江口 智士, 勝田 哲, 北口 貴雄, 太田 直美, 志達 めぐみ, 谷本 敦, 寺島 雄一, 坪井 陽子, 内田 和海, 内田 悠介, 内山 秀樹, 山田 智史, 山内 茂雄, HOLLAND Matt, LOEWENSTEIN Michael, MILLER Eric, YAQOOB Tahir

    2023年度 宇宙科学情報解析シンポジウム     2024年2月

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    記述言語:日本語   出版者・発行元:宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)  

    CiNii Research

  11. Relativistic Runaway Electron Avalanche Development Near the Electric Field Threshold in Inhomogeneous Air 査読有り

    Diniz, GS; Wada, Y; Ohira, Y; Nakazawa, K; Tsurumi, M; Enoto, T

    GEOPHYSICAL RESEARCH LETTERS   50 巻 ( 20 )   2023年10月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Geophysical Research Letters  

    Relativistic Runaway Electrons Avalanches (RREAs) development depends on the applied electric field and the environment's air density. This dependency controls the RREA exponential growth length scale. The RREA development affects the bremsstrahlung excess occurring due to the passage of charged particles through the thundercloud's electric fields, the gamma-ray glow. We used Monte Carlo simulations to develop an empirical model showing the RREA behavior in a realistic atmospheric density profile. The new formulation shows how the density variation modulates the electron population under electric field strengths near the RREA electric field threshold. The model limits the initial RREA altitude range as a function of the electric field strength. The new model is valid between ∼0.6 and ∼18 km, covering the relevant heights to investigate the generation of ground-detected gamma-ray glows.

    DOI: 10.1029/2023GL105087

    Web of Science

    Scopus

  12. 宇宙ガンマ線観測・暗黒物質探索実験GRAMSに向けた液体アルゴン放射線検出器の気球搭載試験(1): 全体報告

    小高 裕和, 袴田 知宏, 善本 真梨那, 青山 一天, 内海 和伸, 田中 雅士, 中島 理幾, 寄田 浩平, 新井 翔太, 加藤 辰明, 高嶋 聡, 馬場 彩, 丹波 翼, 辻 直美, 荒牧 嗣夫, 高橋 弘充, 大熊 佳吾, 中澤 知洋

    大気球シンポジウム: 2023年度     2023年10月

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    記述言語:日本語   出版者・発行元:宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)  

    レポート番号: isas23-sbs-032

    CiNii Research

  13. 狭視野の半導体コンプトンカメラによるsub-MeVイメージャの大気球実験

    中澤 知洋, 武田 伸一郎, 大熊 佳吾, 大宮 悠希, 安藤 美唯, 渡辺 伸, 高橋 忠幸, 小林 昌彦, 石田 直樹, 大口 真奈里, 田中 敦也, 西村 悠太, 大西 光延, 新井 利彦

    大気球シンポジウム: 2023年度     2023年10月

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    記述言語:日本語   出版者・発行元:宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)  

    レポート番号: isas23-sbs-014

    CiNii Research

  14. 宇宙ガンマ線観測・暗黒物質探索実験GRAMSに向けた液体アルゴン放射線検出器の気球搭載試験(2): フライト結果

    青山 一天, 内海 和伸, 田中 雅士, 中島 理幾, 寄田 浩平, 小高 裕和, 袴田 知宏, 善本 真梨那, 新井 翔太, 加藤 辰明, 高嶋 聡, 馬場 彩, 丹波 翼, 辻 直美, 荒牧 嗣夫, 高橋 弘充, 大熊 佳吾, 中澤 知洋

    大気球シンポジウム: 2023年度     2023年10月

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    記述言語:日本語   出版者・発行元:宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)  

    レポート番号: isas23-sbs-033

    CiNii Research

  15. GRBAlpha: The smallest astrophysical space observatory

    Pál, A; Ohno, M; Mészáros, L; Werner, N; Rípa, J; Csák, B; Dafciková, M; Frajt, M; Fukazawa, Y; Hanak, P; Hudec, J; Husáriková, N; Kapus, J; Kasal, M; Kolár, M; Koleda, M; Laszlo, R; Lipovsky, P; Mizuno, T; Münz, F; Nakazawa, K; Rezenov, M; Smelko, M; Takahashi, H; Topinka, M; Urbanec, T; Breuer, JP; Bozóki, T; Dálya, G; Enoto, T; Frei, Z; Friss, G; Galgóczi, G; Hroch, F; Ichinohe, Y; Kapás, K; Kiss, LL; Matake, H; Odaka, H; Poon, H; Povalac, A; Takátsy, J; Torigoe, K; Uchida, N; Uchida, Y

    ASTRONOMY & ASTROPHYSICS   677 巻   2023年8月

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    出版者・発行元:Astronomy and Astrophysics  

    Aims. Since it launched on 22 March 2021, the 1U-sized CubeSat GRBAlpha operates and collects scientific data on high-energy transients, making it the smallest astrophysical space observatory to date. GRBAlpha is an in-orbit demonstration of a gamma-ray burst (GRB) detector concept suitably small to fit into a standard 1U volume. As was demonstrated in a companion paper, GRBAlpha adds significant value to the scientific community with accurate characterization of bright GRBs, including the recent outstanding event of GRB 221009A. Methods. The GRB detector is a 75 × 75 × 5 mm CsI(Tl) scintillator wrapped in a reflective foil (ESR) read out by an array of SiPM detectors, multi-pixel photon counters by Hamamatsu, driven by two separate redundant units. To further protect the scintillator block from sunlight and protect the SiPM detectors from particle radiation, we applied a multi-layer structure of Tedlar wrapping, anodized aluminium casing, and a lead-alloy shielding on one edge of the assembly. The setup allows observations of gamma radiation within the energy range of 70- 890 keV with an energy resolution of ~30%. Results. Here, we summarize the system design of the GRBAlpha mission, including the electronics and software components of the detector, some aspects of the platform, and the current semi-autonomous operations. In addition, details are given about the raw data products and telemetry in order to encourage the community to expand the receiver network for our initiatives with GRBAlpha and related experiments.

    DOI: 10.1051/0004-6361/202346182

    Web of Science

    Scopus

  16. The peak flux of GRB 221009A measured with GRBAlpha

    Rípa, J; Takahashi, H; Fukazawa, Y; Werner, N; Münz, F; Pál, A; Ohno, M; Dafcíková, M; Meszáros, L; Csák, B; Husáriková, N; Kolár, M; Galgóczi, G; Breuer, JP; Hroch, F; Hudec, J; Kapus, J; Frajt, M; Rezenov, M; Laszlo, R; Koleda, M; Smelko, M; Hanák, P; Lipovsky, P; Urbanec, T; Kasal, M; Povalac, A; Uchida, Y; Poon, H; Matake, H; Nakazawa, K; Uchida, N; Bozóki, T; Dálya, G; Enoto, T; Frei, Z; Friss, G; Ichinohe, Y; Kapás, K; Kiss, LL; Mizuno, T; Odaka, H; Takátsy, J; Topinka, M; Torigoe, K

    ASTRONOMY & ASTROPHYSICS   677 巻   2023年8月

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    出版者・発行元:Astronomy and Astrophysics  

    Context. On 2022 October 9 the brightest gamma-ray burst (GRB) ever observed lit up the high-energy sky. It was detected by a multitude of instruments, attracting the close attention of the GRB community, and saturated many detectors. Aims. GRBAlpha, a nano-satellite with a form factor of a 1U CubeSat, detected this extraordinarily bright long-duration GRB, GRB 221009A, without saturation but affected by pile-up. We present light curves of the prompt emission in 13 energy bands, from 80 keV to 950 keV, and performed a spectral analysis to calculate the peak flux and peak isotropic-equivalent luminosity. Methods. Since the satellite s attitude information is not available for the time of this GRB, more than 200 incident directions were probed in order to find the median luminosity and its systematic uncertainty. Results. We find that the peak flux in the 80-800 keV range (observer frame) was Fph p = 1300+ -1200 200 ph cm-2 s-1, or Ferg p = 5:7+ -3 0::7 7×10-4 erg cm-2 s-1, and the fluence in the same energy range of the first GRB episode, which lasted 300 s and was observable by GRBAlpha, was S = 2:2+1:4 -0:3 × 10-2 erg cm-2, or S bol = 4:9+0:8 -0:5 × 10-2 erg cm-2 for the extrapolated range of 0:9-8690 keV. We infer the isotropic-equivalent released energy of the first GRB episode to be Eiso bol = 2:8+ -0 0::8 5 × 1054 erg in the 1-10 000 keV band (rest frame at z = 0:15). The peak isotropic-equivalent luminosity in the 92-920 keV range (rest frame) was Liso p = 3:7+ -2 0::5 5 × 1052 erg s-1, and the bolometric peak isotropic-equivalent luminosity was Lp;bol iso = 8:4+-21::55 × 1052 erg s-1 (4 s scale) in the 1-10 000 keV range (rest frame). The peak emitted energy is Ep*= Ep(1 + z) = 1120 ± 470 keV. Our measurement of Lp;bol iso is consistent with the Yonetoku relation. It is possible that, due to the spectral evolution of this GRB and the orientation of GRBAlpha at the peak time, the true values of peak flux, fluence, Liso, and Eiso are even higher.

    DOI: 10.1051/0004-6361/202346128

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    Scopus

  17. Development of miniSGD, a proof-of-concept balloon experiment for a narrow field of view Si/CdTe semiconductor Compton telescope

    Keigo Okuma, Kazuhiro Nakazawa, Shin'ichiro Takeda, Mii Ando, Yuki Omiya, Manari Oguchi, Atsuya Tanaka, Yuna Tsuji, Shin Watanabe, Tadayuki Takahashi, Masahiko Kobayashi, Naoki Ishida, Takahiro Minami, Mitsunobu Onishi, Toshihiko Arai

    Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)     2023年8月

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Sissa Medialab  

    DOI: 10.22323/1.444.0899

  18. Termination of Downward-Oriented Gamma-Ray Glow by Normal-Polarity In-Cloud Discharge Activity

    Wada, Y; Wu, T; Wang, D; Enoto, T; Nakazawa, K; Morimoto, T; Nakamura, Y; Shinoda, T; Tsuchiya, H

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   128 巻 ( 15 )   2023年8月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Geophysical Research: Atmospheres  

    A gamma-ray glow, a minute-lasting burst of high-energy photons from a thundercloud, was detected by ground-based apparatus at Kanazawa University, Japan, in a winter thunderstorm on 18 December 2018. The gamma-ray glow was quenched by a lightning flash within a brief time window of 40 ms. The lightning flash produced several low-frequency (LF) E-change pulses that were temporally coincident with the termination of the gamma-ray glow, and that were located within 0.5 km from the observation site by the Fast Antenna Lightning Mapping Array. The LF pulses had the same polarity as a positive cloud-to-ground current and a normal-polarity in-cloud current. Since this polarity is against the upward electric field for producing the gamma-ray glow (accelerating electrons to the ground), we infer that the glow was terminated by a normal-polarity in-cloud discharge activity between a middle negative layer and an upper positive layer.

    DOI: 10.1029/2023JD038606

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  19. Citizen science "Thundercloud Project" -- multi-point radiation measurements of gamma-ray glows from accelerated electrons in thunderstorms

    Teruaki Enoto, Miwa Tsurumi, Yuko Ikkatai, Ting Wu, Daohong Wang, Taro Shinoda, Kazuhiro Nakazawa, Naoki Tsuji, Gabriel Diniz, Jun Kataoka, Masashi Kamogawa, Toru Takagaki, Shoko Miyake, Takeshi Morimoto, Yoshitaka Nakamura, Harufumi Tsuchiya

    Proceedings of 38th International Cosmic Ray Conference — PoS(ICRC2023)     2023年8月

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Sissa Medialab  

    DOI: 10.22323/1.444.1607

  20. Citizen Science Observation of a Gamma-Ray Glow Associated With the Initiation of a Lightning Flash

    Tsurumi, M; Enoto, T; Ikkatai, Y; Wu, T; Wang, D; Shinoda, T; Nakazawa, K; Tsuji, N; Diniz, GS; Kataoka, J; Koshikawa, N; Iwashita, R; Kamogawa, M; Takagaki, T; Miyake, S; Tomioka, D; Morimoto, T; Nakamura, Y; Tsuchiya, H

    GEOPHYSICAL RESEARCH LETTERS   50 巻 ( 13 )   2023年7月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Geophysical Research Letters  

    Gamma-ray glows are observational evidence of relativistic electron acceleration due to the electric field in thunderclouds. However, it is yet to be understood whether such relativistic electrons contribute to the initiation of lightning discharges. To tackle this question, we started the citizen science “Thundercloud Project,” where we map radiation measurements of glows from winter thunderclouds along Japan's sea coast area. We developed and deployed 58 compact gamma-ray monitors at the end of 2021. On 30 December 2021, five monitors simultaneously detected a glow with its radiation distribution horizontally extending for 2 km. The glow terminated coinciding with a lightning flash at 04:08:34 JST, which was recorded by the two radio-band lightning mapping systems, FALMA and DALMA. The initial discharges during the preliminary breakdown started above the glow, that is, in vicinity of the electron acceleration site. This result provides one example of possible connections between electron acceleration and lightning initiation.

    DOI: 10.1029/2023GL103612

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  21. Citizen Science Observation of a Gamma‐Ray Glow Associated With the Initiation of a Lightning Flash

    Tsurumi M., Enoto T., Ikkatai Y., Wu T., Wang D., Shinoda T., Nakazawa K., Tsuji N., Diniz G. S., Kataoka J., Koshikawa N., Iwashita R., Kamogawa M., Takagaki T., Miyake S., Tomioka D., Morimoto T., Nakamura Y., Tsuchiya H.

    Geophysical Research Letters   50 巻 ( 13 )   2023年7月

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    記述言語:英語  

    Gamma-ray glows are observational evidence of relativistic electron acceleration due to the electric field in thunderclouds. However, it is yet to be understood whether such relativistic electrons contribute to the initiation of lightning discharges. To tackle this question, we started the citizen science “Thundercloud Project, ” where we map radiation measurements of glows from winter thunderclouds along Japan's sea coast area. We developed and deployed 58 compact gamma-ray monitors at the end of 2021. On 30 December 2021, five monitors simultaneously detected a glow with its radiation distribution horizontally extending for 2 km. The glow terminated coinciding with a lightning flash at 04:08:34 JST, which was recorded by the two radio-band lightning mapping systems, FALMA and DALMA. The initial discharges during the preliminary breakdown started above the glow, that is, in vicinity of the electron acceleration site. This result provides one example of possible connections between electron acceleration and lightning initiation.

    CiNii Research

  22. Ambient Conditions of Winter Thunderstorms in Japan to Reproduce Observed Gamma-Ray Glow Energy Spectra

    Diniz, GS; Wada, Y; Ohira, Y; Nakazawa, K; Tsurumi, M; Enoto, T

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   128 巻 ( 10 )   2023年5月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Geophysical Research: Atmospheres  

    Electric field of thunderclouds modifies components and energy spectra of the cosmic-ray air shower. In particular, thunderstorms accelerate charged particles, resulting in an enhancement of gamma-ray fluxes on the ground, known as a gamma-ray glow. This phenomenon has been observed in recent years by the Gamma-Ray Observation of Winter THunderclouds collaboration from winter thunderstorms in the Hokuriku area of Japan. The present work examines the ambient conditions required to produce spectral features of the previously detected gamma-ray glows, by using Monte Carlo simulations of particle interactions in the atmosphere. We focus on three parameters, the strength and length of the electric field, and the length of a null-field attenuation region below the electrified region. The average spectrum of observed gamma-ray glows in winter thunderstorms of Japan requires an electric field intensity close to 0.31 MV/m, slightly exceeding the Relativistic Runaway Electron Avalanche threshold of 0.284 MV/m. The vertical size of the electric field region should be comparable to 1 km. The estimated attenuation region size is 300–500 m, necessary to reduce the low-energy photon flux of the average gamma-ray glows. There is still a wide range of acceptable parameter sets with degeneracy to make a similar spectrum.

    DOI: 10.1029/2022JD038246

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  23. Diffuse radio source candidate in CIZA J1358.9-4750

    Kurahara, K; Akahori, T; Kale, R; Akamatsu, H; Fujita, Y; Gu, LY; Intema, H; Nakazawa, K; Okabe, N; Omiya, Y; Parekh, V; Shimwell, T; Takizawa, M; Van Weeren, RJ

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   75 巻 ( Supplement_1 ) 頁: S138 - S153   2023年2月

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    掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    We report on results of our upgraded Giant Metrewave Radio Telescope (uGMRT) observations for an early-stage merging galaxy cluster, CIZA J1358.9−4750 (CIZA1359), in Band-3 (300–500 MHz). We achieved the image dynamic range of ∼38000 using the direction dependent calibration and found a candidate of diffuse radio emission at 4σrms significance. The flux density of the candidate at 400 MHz, 24.04 ± 2.48 mJy, is significantly positive compared to noise, where its radio power, 2.40 × 1024 W Hz−1, is consistent with those of typical diffuse radio sources of galaxy clusters. The candidate is associated with a part of the X-ray shock front at which the Mach number reaches its maximum value of M ∼ 1.7. The spectral index (Fν ∝ να) of the candidate, α = −1.22 ± 0.33, is in agreement with an expected value derived from the standard diffusive shock acceleration (DSA) model. However, such a low Mach number with a short acceleration time would require seed cosmic rays supplied from active galactic nucleus (AGN) activities of member galaxies, as suggested in some other clusters. Indeed, we found seven AGN candidates inside the diffuse source candidate. Assuming the energy equipartition between magnetic fields and cosmic rays, the magnetic field strength of the candidate was estimated to be 2.1 μG. We also find head–tail galaxies and radio phoenixes or fossils near CIZA1359.

    DOI: 10.1093/pasj/psac098

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  24. XMM-Newton view of the shock heating in an early merging cluster, CIZA J1358.9-4750 査読有り

    Omiya, Y; Nakazawa, K; Matsushita, K; Kobayashi, SB; Okabe, N; Sato, K; Tamura, T; Fujita, Y; Gu, LY; Kitayama, T; Akahori, T; Kurahara, K; Yamaguchi, T

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   75 巻 ( 1 ) 頁: 37 - 51   2023年2月

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    出版者・発行元:Publications of the Astronomical Society of Japan  

    CIZA J1358.9−4750 is a nearby galaxy cluster in the early phase of a major merger. The two-dimensional temperature map using XMM-Newton EPIC-PN observation confirms the existence of a high-temperature region, which we call the “hot region,” in the “bridge region” connecting the two clusters. The ∼500 kpc wide region between the south-east and north-west boundaries also has higher pseudo-pressure compared to the unshocked regions, suggesting the existence of two shocks. The southern shock front is clearly visible in the X-ray surface brightness image and has already been reported by Kato et al. (2015, PASJ, 67, 71). The northern one, on the other hand, is newly discovered. To evaluate their Mach number, we constructed a three-dimensional toy merger model with overlapping shocked and unshocked components in the line of sight. The unshocked and pre-shock intracluster medium (ICM) conditions are estimated based on those outside the interacting bridge region, assuming point symmetry. The hot-region spectra are modeled with two-temperature thermal components, assuming that the shocked condition follows the Rankin–Hugoniot relation with the pre-shock condition. As a result, the shocked region is estimated to have a line-of-sight depth of ∼1 Mpc with a Mach number of ∼1.3 in the south-east shock and ∼1.7 in the north-west shock. The age of the shock waves is estimated to be ∼260 Myr. This three-dimensional merger model is consistent with the Sunyaev–Zel’dovich signal obtained using the Planck observation within the cosmic microwave background fluctuations. The total flow of the kinetic energy of the ICM through the south-east shock was estimated to be ∼2.2 × 1042 erg s−1. Assuming that 10% of this energy is converted into ICM turbulence, the line–of–sight velocity dispersion is calculated to be ∼200 km s−1, which is basically resolvable via upcoming high spectral resolution observations.

    DOI: 10.1093/pasj/psac087

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    arXiv

    その他リンク: http://arxiv.org/pdf/2210.02145v2

  25. Solar Neutron and Gamma-ray Spectroscopy Mission: SONGS

    Yamaoka K., Tajima H., Nobashi D., Usami M., Miyata K., Inamori T., Park J.H., Ito K., Matsushita K., Watabe T., Nakazawa K., Masuda S., Takahashi H., Watanabe K.

    Proceedings of Science   395 巻   2022年3月

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    出版者・発行元:Proceedings of Science  

    Fast neutrons generated by the interaction between ions and the solar atmosphere are important observation problems to clarify the ion acceleration mechanism in the Sun, but so far neutrons have been detected from only 12 X-class solar flares in the highland on the ground due to the influence of atmospheric absorption. As for observations in space, SEDA-AP at the International Space Station continued to operate until 2018 and succeeded in neutron detection from 52 solar flares, but there are currently no dedicated space missions. In order to overcome this situation, we have been designing and developing 3U CubeSat and novel neutron/gamma-ray sensors since 2018 with the aim of performing satellite observations from outer space. The sensor consists of the multi-layered plastic scintillator bars readout with Si PM, which is a semiconductor photo-sensor, and detects fast neutrons from the tracks of ejected protons by elastic scattering. Furthermore, by placing GAGG scintillator arrays at the bottom, it is designed to be sensitive to gamma-rays based on the principle of the Compton camera. In this presentation, we will report on the scientific motivation and the development status of CubeSat and neutron/gamma-ray sensors.

    Scopus

  26. Solar Neutron and Gamma-ray Spectroscopy Mission: SONGS

    Kazutaka Yamaoka, Hiroyasu Tajima, Daiki Nobashi, Masaki Usami, Kikuko Miyata, Takaya Inamori, Ji Hyun Park, Kazuya Ito, Koji Matsushita, Toyoki Watabe, Kazuhiro Nakazawa, Satoshi Masuda, Hiromitsu Takahashi, Kyoko Watanabe

    Proceedings of Science   395 巻   2022年3月

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    掲載種別:研究論文(国際会議プロシーディングス)  

    Fast neutrons generated by the interaction between ions and the solar atmosphere are important observation problems to clarify the ion acceleration mechanism in the Sun, but so far neutrons have been detected from only 12 X-class solar flares in the highland on the ground due to the influence of atmospheric absorption. As for observations in space, SEDA-AP at the International Space Station continued to operate until 2018 and succeeded in neutron detection from 52 solar flares, but there are currently no dedicated space missions. In order to overcome this situation, we have been designing and developing 3U CubeSat and novel neutron/gamma-ray sensors since 2018 with the aim of performing satellite observations from outer space. The sensor consists of the multi-layered plastic scintillator bars readout with Si PM, which is a semiconductor photo-sensor, and detects fast neutrons from the tracks of ejected protons by elastic scattering. Furthermore, by placing GAGG scintillator arrays at the bottom, it is designed to be sensitive to gamma-rays based on the principle of the Compton camera. In this presentation, we will report on the scientific motivation and the development status of CubeSat and neutron/gamma-ray sensors.

    Scopus

  27. Characteristics of Low-Frequency Pulses Associated With Downward Terrestrial Gamma-Ray Flashes

    Wada, Y; Morimoto, T; Nakamura, Y; Wu, T; Enoto, T; Nakazawa, K; Ushio, T; Yuasa, T; Tsuchiya, H

    GEOPHYSICAL RESEARCH LETTERS   49 巻 ( 5 )   2022年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Geophysical Research Letters  

    Winter thunderstorms in Japan have been recognized as an ideal target to observe high-energy atmospheric phenomena thanks to low-charge-center cloud structures. During four winter seasons in Japan (from 2016 October to 2020 March), seven downward terrestrial gamma-ray flashes (TGFs) were detected by gamma-ray and broadband low-frequency (LF: 0.8–500 kHz) monitors. All the detected TGFs took place at the initial stage of lightning flashes. Based on the LF observation, the seven downward TGFs in the present study can be classified into two types: energetic-bipolar and small-bipolar types. Three of them are energetic-bipolar events, coincident with a high peak-current LF pulse that originates from a negative return stroke with a peak current larger than 100 kA. The others are small-bipolar events, followed by a negative bipolar LF pulse with a moderate peak current. Three of the four small-bipolar events are multi-pulse TGFs, while all of the energetic-bipolar events in this study are single-pulse TGFs.

    DOI: 10.1029/2021GL097348

    Web of Science

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    その他リンク: https://onlinelibrary.wiley.com/doi/full-xml/10.1029/2021GL097348

  28. Atmospheric Electron Spatial Range Extended by Thundercloud Electric Field Below the Relativistic Runaway Electron Avalanche Threshold

    Diniz, G; Wada, Y; Ohira, Y; Nakazawa, K; Enoto, T

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   127 巻 ( 3 )   2022年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Geophysical Research: Atmospheres  

    Cosmic-ray shower, hitting the atmosphere all the time, includes high-energy electrons. Electric fields in thunderstorms accelerate these electrons so that they can reach farther distances with producing secondary electrons. The strong field above 0.284 MV m−1 causes the Relativistic Runaway Electron Avalanches (RREA) process with an exponential increase of electrons. Even with lower electric fields below this RREA threshold which are usually measured in thunderstorms, an increase in electrons' kinetic energy and production of secondary electrons can occur without avalanche processes, known as Modification Of Spectra (MOS) of the cosmic-ray shower. Both phenomena are related to observed gamma ray glow, which is bremsstrahlung emission from accelerated electrons in thunderstorms. We calculate an extended range and kinetic energy of electrons below the RREA threshold using an analytical evaluation and Geant4 Monte Carlo simulations. For example, at 0.280 MV m−1 slightly below the RREA threshold, 3 MeV electrons gain 100% of their original kinetic energy through the passage of the continuous slowing down approximation (CSDA) range defined at the null electric field, which is consistent with results in previous studies as the transition to the RREA process. Even at a lower field of 0.260 MV m−1, the energy recovery by the field allows an injected 20 MeV electron beam to extend its average electron range from 73 m, in the null field configuration, to 562 m. We have performed analytical calculation and Geant4 simulations of atmospheric electron behavior for initial electron energy of 0.1–100 MeV and an electric field below 0.290 MV m−1.

    DOI: 10.1029/2021JD035958

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    その他リンク: https://onlinelibrary.wiley.com/doi/full-xml/10.1029/2021JD035958

  29. Balloon-borne narrow field of view Semiconductor Compton telescope concept - miniSGD -

    Nakazawa, K; Okuma, K; Tsuji, Y; Takeda, S; Ando, M; Omiya, Y; Oguchi, M; Tanaka, A; Watanabe, S; Takahashi, T; Onishi, M; Arai, T; Kobayashi, M; Ishida, N

    SPACE TELESCOPES AND INSTRUMENTATION 2022: ULTRAVIOLET TO GAMMA RAY   12181 巻   2022年

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    The MeV band covers the physics of the lowest energy end of the non-thermal universe and nuclear reactions in metal synthesis and/or matters interacting with cosmic rays. Nevertheless, sensitivity in this band is still limited. Improving MeV sensitivity is one of the most important issues in modern astronomy. The soft gamma-ray detector (SGD) onboard the Hitomi satellite launched in 2016 was an innovative narrow field-of-view semiconductor Compton telescope (SCT), which aims at background reduction through deep active-shielding combined with SCT using Si and CdTe, a Si/CdTe-SCT. Although with a limited operation time, it is the sole SCT proven in orbit to date, and succeeded in detecting ∼ 100 keV polarization with only 5 ks exposure. Based on these achievements, we propose a new approach “narrow field-of-view Si/CdTe-SCT at balloon altitude”. At the altitude of 32-40 km, detectors do not suffer severe proton bomberment, which was one of the major contributor to the SGD background, while able to observe MeV gamma rays from the universe. Atmospheric gamma rays is non-negligible, but as it is stronger near horizon, narrowing the field-of-view and aiming around zenith will cut most of them. The detector loses wide field of view, but can be used as a probe in sub-MeV band. As the first step of this approach, we are planning a balloon experiment, miniSGD, to confirm the concept. It is very compact and not aiming at real observation, but has all the components integrated within the 40 × 40 × 50 cm3 volume, including detectors, electronics and the collimator. The Si/CdTe-SCT was made of a single layer of 0.5 mm thick double-sided Si strip detectors (DSSDs) and newly developed 2 mm thick CdTe double sided strip detectors (CdTe-DSDs), surrounded by nine units of 2-3 cm thick BGO scintillator crystals. The miniSGD experiment is to fly as a piggy-back payload in the 2023 Spring campaign of JAXA Ballooning team at Alice Springs, Australia. Technologies to be verified in miniSGD are also applicable to the future hard X-ray missions, such as the FORCE mission.

    DOI: 10.1117/12.2628199

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  30. Xappl: Software Framework for the XRISM Pre-Pipeline

    Eguchi, S; Tashiro, M; Terada, Y; Takahashi, H; Nobukawa, M; Mizuno, T; Uno, S; Kubota, A; Nakazawa, K; Watanabe, S; Iizuka, R; Sato, R; Yoneyama, T; Baluta, C; Ebisawa, K; Fukazawa, Y; Hayashi, K; Kato, S; Katsuda, S; Kitaguchi, T; Odaka, H; Ohno, M; Ota, N; Sakama, M; Sato, R; Shidatsu, M; Sugawara, Y; Tamba, T; Tanimoto, A; Terashima, Y; Tsuboi, Y; Uchida, N; Uchida, Y; Uchiyama, H; Yamauchi, S; Sakano, M; Yoshida, T; Yamada, S

    SPACE TELESCOPES AND INSTRUMENTATION 2022: ULTRAVIOLET TO GAMMA RAY   12181 巻   2022年

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    Xappl is a software framework written in Python to build pre-pipelines for the X-Ray Imaging and Spectroscopy Mission (XRISM) scheduled to be launched in the Japanese fiscal year 2022. Xappl chains software tasks in the order specified in configuration files in the INI format, enabling us to reduce the telemetry data to First FITS Files, which originate datasets ready for analysis. Since the functionalities of Xappl are highly generalized, it is reusable for future missions. In this paper, we present the design of Xappl and report the developmental progress of the pre-pipeline for XRISM.

    DOI: 10.1117/12.2629316

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  31. SOlar Neutron and Gamma-ray Spectroscopy Mission (SONGS)

    Yamaoka, K; Tajima, H; Miyata, K; Usami, M; Watabe, T; Matsushita, K; Ito, K; Nakazawa, K; Masuda, S; Tani, K; Arai, M; Hatori, S; Kume, K; Mizushima, S; Takahashi, H; Watanabe, K

    SPACE TELESCOPES AND INSTRUMENTATION 2022: ULTRAVIOLET TO GAMMA RAY   12181 巻   2022年

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    The SOlar Neutron and Gamma-ray Spectroscopy (SONGS) mission is a 3U cubesat dedicated for detecting neutrons and gamma-rays associated with intense solar flares. Solar neutron observations have not been in progress because ground-based observations are affected by attenuation in the Earth atmosphere, and there is no dedicated mission in space at present. Hence, we are now developing in collaboration between science and engineering people at universities, and preparing for launch around 2024 during the next solar maximum. The SONGS carries a novel radiation detector which consists of multi-layered plastic scintillator bars and GAGG(Ce) scintillator array so that it can determine energies for both neutrons and gamma-rays. In total 704 signals from Silicon photo-multipliers (SiPMs) are processed by 45 ASICs with very low power consumption, and realized within limited resources. In this presentation, we will describe scientific motivation, mission and instrument overview, and results from the bread-board model (BBM).

    DOI: 10.1117/12.2629131

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  32. Early results from GRBAlpha and VZLUSAT-2

    Rípa, J; Pál, A; Ohno, M; Werner, N; Mészáros, L; Csák, B; Dafcikova, M; Dániel, V; Dudás, J; Frajt, M; Hanák, P; Hudec, J; Junas, M; Kapus, J; Kasal, M; Koleda, M; Laszlo, R; Lipovsky, P; Münz, F; Rezenov, M; Smelko, M; Svoboda, P; Takahashi, H; Topinka, M; Urbanec, T; Breuer, JP; Enoto, T; Frei, Z; Fukazawa, Y; Galgóczi, G; Hroch, F; Ichinohe, Y; Kiss, L; Matake, H; Mizuno, T; Nakazawa, K; Odaka, H; Poon, H; Uchida, N; Uchida, Y

    SPACE TELESCOPES AND INSTRUMENTATION 2022: ULTRAVIOLET TO GAMMA RAY   12181 巻   2022年

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    出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    We present the detector performance and early science results from GRBAlpha, a 1U CubeSat mission, which is a technological pathfinder to a future constellation of nanosatellites monitoring gamma-ray bursts (GRBs). GRBAlpha was launched in March 2021 and operates on a 550 km altitude sun-synchronous orbit. The gamma-ray burst detector onboard GRBAlpha consists of a 75×75×5 mm CsI(Tl) scintillator, read out by a dual-channel multi-pixel photon counter (MPPC) setup. It is sensitive in the a1/430-900 keV range. The main goal of GRBAlpha is the in-orbit demonstration of the detector concept, verification of the detector's lifetime, and measurement of the background level on low-Earth orbit, including regions inside the outer Van Allen radiation belt and in the South Atlantic anomaly. GRBAlpha has already detected five, both long and short, GRBs and two bursts were detected within a time-span of only 8 hours, proving that nanosatellites can be used for routine detection of gamma-ray transients. For one GRB, we were able to obtain a high resolution spectrum and compare it with measurements from the Swift satellite. We find that, due to the variable background, the time fraction of about 67% of the low-Earth polar orbit is suitable for gamma-ray burst detection. One year after launch, the detector performance is good and the degradation of the MPPC photon counters remains at an acceptable level. The same detector system, but double in size, was launched in January 2022 on VZLUSAT-2 (3U CubeSat). It performs well and already detected three GRBs and two solar flares. Here, we present early results from this mission as well.

    DOI: 10.1117/12.2629332

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  33. Current status of development of lightweight X-ray mirror with Carbon Fiber Reinforced Plastic (CFRP)

    Awaki, H; Kametani, N; Imamura, R; Ishida, M; Iwasaki, M; Kodani, K; Maeda, Y; Matsumoto, H; Mori, K; Nakazawa, K; Ozaki, T; Suzuki, H; Takahashi, H; Tsuru, T; Utsunomiya, S

    SPACE TELESCOPES AND INSTRUMENTATION 2022: ULTRAVIOLET TO GAMMA RAY   12181 巻   2022年

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    CFRP is a composite material composed of carbon fiber and resin. CFRP is commonly applied to the aerospace industry which requires lightweight and intensity. Thanks to superior formability of CFRP, we can form shape of Wolter-1 optics, which consists of paraboloid and hyperboloid, to a monolithic substrate. Since the surface roughness of CFRP substrate is a few microns, it is required to make the smooth surface for reflecting X-rays on the CFRP substrate. We have developed a new method of shaping the reflective surface by pasting thin sheet-glass with 50~100 µm thick onto the CFRP substrate. The surface roughness of the thin sheet-glass was measured to about 0.4 nm by Zygo. Our CFRP mirror is a candidate for backup mirrors in the FORCE mission, and are being developed for balloon-borne experiments planned in the near future. Current image quality of our CFRP mirror was measured to be about 60-120 arcsec by illuminating an X-ray pencil beam at the ISAS beam line. In order to achieve a high imaging quality less than 15 arcsec, we will improve the CFRP mirror surface using both the replica method, and an ultra-precision mold processed with a shape error of 0.1 µm or less. The mold will be completed in the summer of 2022. We report on the current status of the development of the CFRP mirrors.

    DOI: 10.1117/12.2629705

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  34. Catalog of gamma-ray glows during four winter seasons in Japan

    Wada, Y; Matsumoto, T; Enoto, T; Nakazawa, K; Yuasa, T; Furuta, Y; Yonetoku, D; Sawano, T; Okada, G; Nanto, H; Hisadomi, S; Tsuji, Y; Diniz, GS; Makishima, K; Tsuchiya, H

    PHYSICAL REVIEW RESEARCH   3 巻 ( 4 )   2021年11月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review Research  

    In 2015, the Gamma-Ray Observation of Winter Thunderstorms (GROWTH) collaboration launched a mapping observation campaign for high-energy atmospheric phenomena related to thunderstorms and lightning discharges. This campaign has developed a detection network of gamma rays with up to 10 radiation monitors installed in the cities of Kanazawa and Komatsu, Ishikawa Prefecture, Japan, where low-charge-center winter thunderstorms frequently occur. During four winter seasons from October 2016 to April 2020, a total of 70 gamma-ray glows, i.e., minute-lasting bursts of gamma rays originating from thunderclouds, were detected. Their average duration is 58.9 s. Among the detected events, 77% were observed at night. The gamma-ray glows can be classified into temporally symmetric, temporally asymmetric, and lightning-terminated types based on their count-rate histories. An averaged energy spectrum of the gamma-ray glows is well fitted with a power-law function with an exponential cutoff, whose photon index, cutoff energy, and flux are 0.613±0.009 MeV, 4.68±0.04 MeV, and (1.013±0.003)×10-5 erg cm-2s-1 (0.2-20.0 MeV), respectively. The present paper provides a catalog of gamma-ray glows and their statistical analysis detected during winter thunderstorms in the Kanazawa and Komatsu areas.

    DOI: 10.1103/PhysRevResearch.3.043117

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    その他リンク: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevResearch.3.043117/fulltext

  35. Multiple Gamma-Ray Glows and a Downward TGF Observed From Nearby Thunderclouds

    Hisadomi, S; Nakazawa, K; Wada, Y; Tsuji, Y; Enoto, T; Shinoda, T; Morimoto, T; Nakamura, Y; Yuasa, T; Tsuchiya, H

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   126 巻 ( 18 )   2021年9月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Geophysical Research: Atmospheres  

    Around 17:00 on January 12, 2020 (UTC), radiation detectors installed at two locations with a 1.35 km separation in Kanazawa City, Japan, captured a total of four gamma-ray enhancements. The first pair was simultaneously observed at the two locations at 17:03 and were abruptly terminated by a lightning discharge. The remaining two enhancements were also nearly simultaneously observed (Formula presented.) 3 min later, and one of them was also terminated by another lightning discharge. At the last termination, a downward terrestrial gamma-ray flash and a negative energetic in-cloud pulse were observed. Both pairs were associated with thundercloud cells. In the first pair, simultaneous detection in two locations 1.35 km apart suggests either a gamma-ray glow emerged in-between and time variability of its intensity were directly observed or there were two (or more) gamma-ray glows in the cell which reached the two detectors coincidentally. In the latter pair, the peak time in the downwind detector was (Formula presented.) 40 s later than that of the upwind detector. If the irradiation region moved with the cell, it would have taken ∼110 s. The discrepancy suggests either the glow moved 2.5 times faster than the cell or there were two (or more) glows in the cell. Also, the fact that the thunderstorm cell hosting the latter glows experienced the lightning discharge (Formula presented.) 3 min before suggests that the strong electric field in the cell can develop within a few minutes.

    DOI: 10.1029/2021JD034543

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  36. Gamma-ray observations at the coastal area of Japan Sea in winter seasons

    Tsuchiya H., Enoto T., Wada Y., Furuta Y., Nakazawa K., Yuasa T., Umemoto D., Makishima K.

    Proceedings of Science   358 巻   2021年7月

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    出版者・発行元:Proceedings of Science  

    Since 2006, The Gamma Ray Observation of Winter Thunderclouds (GROWTH) collaboration has operated radiation measurement networks at the coastal area of Japan sea. The area is famous for its frequent occurrence of winter thunderstorms. We aims at elucidating how particles in lightning and thunderclouds are accelerated to relativistic energies. More than 10-years observations reveal that there are two types of radiation bursts associated with winter thunderstorms. One is a "long burst" or a "gamma-ray glow" lasting for a few tens of seconds to a few minutes. The other is a "short burst" in association with lightning. In order to expand the observational network, we have developed a small type of a radiation detector. In this paper, we focus on recent several findings obtained by the new detectors. One is a combination of a short burst and a long one, showing simultaneous detection of prompt gamma rays extending to ∼10 MeV and the 511-keV annihilation ones. These gamma-ray signals demonstrate the occurrence of photonuclear reactions in lightning. Another is an event that a gamma-ray glow suddenly ceased just prior to lightning, suggesting a relation between lightning and the two types of radiation bursts. On the basis of these results, we discuss the production mechanism of gamma rays related to thunderstorms and the lightning initiation problem.

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  37. Solar Neutron and Gamma-ray Detector for a 3U CubeSat

    Yamaoka K., Tajima H., Miyata K., Inamori T., Sasai Y., Kawahara H., Park J.H., Nakazawa K., Masuda S., Matsushita K., Itoh K., Nobashi D., Takahashi H., Watanabe K.

    Proceedings of Science   358 巻   2021年7月

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    出版者・発行元:Proceedings of Science  

    Solar neutron observations are very important on understanding of particle acceleration mechanism in the Sun. However, previous ground-based observations with large area telescope (∼10 m2)at high latitude are not sensitive to solar neutrons due to attenuation in the earth atmosphere and roughly 10 detection since its discovery in 1980. From space, the SEDA-AP instrument with much smaller area (100 cm2) onboard the International Space Station (ISS) monitored solar neutrons including charged particles, and successfully detected more than 30 detection since its launch in 2009. Unfortunately the SEDA-AP operation was stopped on March 2018. To overcome situation for no mission dedicated for solar neutrons, we have designed and developed a solar neutron and gamma-ray detector for a 3U cubesat with a size of 30×10×10 cm. Actually we launched the 50-kg class ChubuSat-2 satellite for solar neutron observations on February 2016, and have now been adjusting it to a 3U cubesat application. The solar neutron and gamma-ray detector consists of multi-layered plastic scintillator bars, and GAGG(Ce) scintillator array, and both of them are read out with silicon photo-multipliers (Si PMs). More than 600 signals from Si PMs are processed by ASICs. In this paper, we will describe details of the detector and performance of its breadboard model (BBM).

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  38. Detailed design of the science operations for the XRISM mission 査読有り

    Terada, Y; Holland, M; Loewenstein, M; Tashiro, M; Takahashi, H; Nobukawa, M; Mizuno, T; Tamura, T; Uno, S; Watanabe, S; Baluta, C; Burns, L; Ebisawa, K; Eguchi, S; Fukazawa, Y; Hayashi, K; Iizuka, R; Katsuda, S; Kitaguchi, T; Kubota, A; Miller, E; Mukai, K; Nakashima, S; Nakazawa, K; Odaka, H; Ohno, M; Ota, N; Sato, R; Sawada, M; Sugawara, Y; Shidatsu, M; Tamba, T; Tanimoto, A; Terashima, Y; Tsuboi, Y; Uchida, Y; Uchiyama, H; Yamauchi, S; Yaqoob, T

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   7 巻 ( 3 )   2021年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    X-Ray Imaging and Spectroscopy Mission (XRISM) is an x-ray astronomical mission led by the Japan Aerospace Exploration Agency (JAXA) and National Aeronautics and Space Administration (NASA), with collaboration from the European Space Agency (ESA) and other international participants, that is planned for launch in 2022 (Japanese fiscal year), to quickly restore high-resolution x-ray spectroscopy of astrophysical objects using the microcalorimeter array after the loss of Hitomi satellite. In order to enhance the scientific outputs of the mission, the Science Operations Team (SOT) is structured independently from the Instrument Teams (ITs) and the Mission Operations Team. The responsibilities of the SOT are divided into four categories: (1) guest observer program and data distributions, (2) distribution of analysis software and the calibration database, (3) guest observer support activities, and (4) performance verification and optimization activities. Before constructing the operations concept of the XRISM mission, lessons on the science operations learned from past Japanese x-ray missions (ASCA, Suzaku, and Hitomi) are reviewed, and 15 kinds of lessons are identified by categories, such as lessons on the importance of avoiding non-public ("animal") tools, coding quality of public tools in terms of the engineering viewpoint and calibration accuracy, tight communications with ITs and operations teams, and well-defined task division between scientists and engineers. Among these lessons, (a) the importance of early preparation of the operations from the ground stage, (b) construction of an independent team for science operations separate from the instrument development, and (c) operations with well-defined duties by appointed members are recognized as key lessons for XRISM. Based on this, (i) the task division between the mission and science operations and (ii) the subgroup structure within the XRISM Team are defined in detail as the XRISM operations concept. Based on this operations concept, the detailed plan of the science operations is designed as follows. The science operations tasks are shared among Japan, the USA, and Europe and are performed by three centers: the Science Operations Center (SOC) at JAXA, the Science Data Center (SDC) at NASA, and European Space Astronomy Centre (ESAC) at the ESA. The SOT is defined as a combination of the SOC and SDC. The SOC is designed to perform tasks close to the spacecraft operations, such as spacecraft planning of science targets, quick-look health checks, and prepipeline data processing. The SDC covers tasks regarding data calibration processing (pipeline processing) and maintenance of analysis tools. The data-archive and user-support activities are planned to be covered both by the SOC and SDC. Finally, the details of the science operations tasks and the tools for science operations are defined and prepared before launch. This information is expected to be helpful for the construction of science operations of future x-ray missions.

    DOI: 10.1117/1.JATIS.7.3.037001

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  39. Current status of space gravitational wave antenna DECIGO and B-DECIGO

    Kawamura, S; Ando, M; Seto, N; Sato, S; Musha, M; Kawano, I; Yokoyama, J; Tanaka, T; Ioka, K; Akutsu, T; Takashima, T; Agatsuma, K; Araya, A; Aritomi, N; Asada, H; Chiba, T; Eguchi, S; Enoki, M; Fujimoto, MK; Fujita, R; Futamase, T; Harada, T; Hayama, K; Himemoto, Y; Hiramatsu, T; Hong, FL; Hosokawa, M; Ichiki, K; Ikari, S; Ishihara, H; Ishikawa, T; Itoh, Y; Ito, T; Iwaguchi, S; Izumi, K; Kanda, N; Kanemura, S; Kawazoe, F; Kobayashi, S; Kohri, K; Kojima, Y; Kokeyama, K; Kotake, K; Kuroyanagi, S; Maeda, K; Matsushita, S; Michimura, Y; Morimoto, T; Mukohyama, S; Nagano, K; Nagano, S; Naito, T; Nakamura, K; Nakamura, T; Nakano, H; Nakao, K; Nakasuka, S; Nakayama, Y; Nakazawa, K; Nishizawa, A; Ohkawa, M; Oohara, K; Sago, N; Saijo, M; Sakagami, M; Sakai, S; Sato, T; Shibata, M; Shinkai, H; Shoda, A; Somiya, K; Sotani, H; Takahashi, R; Takahashi, H; Akiteru, T; Taniguchi, K; Taruya, A; Tsubono, K; Tsujikawa, S; Ueda, A; Ueda, K; Watanabe, I; Yagi, K; Yamada, R; Yokoyama, S; Yoo, CM; Zhu, ZH

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2021 巻 ( 5 )   2021年5月

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    記述言語:日本語   出版者・発行元:Progress of Theoretical and Experimental Physics  

    The Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is a future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection of primordial gravitational waves, which could have been produced during the inflationary period right after the birth of the Universe. There are many other scientific objectives of DECIGO, including the direct measurement of the acceleration of the expansion of the Universe, and reliable and accurate predictions of the timing and locations of neutron star/black hole binary coalescences. DECIGO consists of four clusters of observatories placed in heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry-Pérot Michelson interferometers with an arm length of 1000 km. Three DECIGO clusters will be placed far from each other, and the fourth will be placed in the same position as one of the other three to obtain correlation signals for the detection of primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder for DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand multi-messenger astronomy.

    DOI: 10.1093/ptep/ptab019

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  40. Meteorological Aspects of Gamma-Ray Glows in Winter Thunderstorms

    Wada, Y; Enoto, T; Kubo, M; Nakazawa, K; Shinoda, T; Yonetoku, D; Sawano, T; Yuasa, T; Ushio, T; Sato, Y; Diniz, GS; Tsuchiya, H

    GEOPHYSICAL RESEARCH LETTERS   48 巻 ( 7 )   2021年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Geophysical Research Letters  

    During three winter seasons from November 2016 to March 2019, 11 gamma-ray glows were detected at a single observation site of our ground-based gamma-ray monitoring network in Kanazawa, Japan. These events are analyzed with observations of an X-band radar network, a ceilometer, a disdrometer, and a weather monitor. All the detected glows were connected to convective high-reflectivity regions of more than 35 dBZ, developed up to an altitude of >2 km. They were also accompanied by heavy precipitation of graupels. Therefore, graupels in the lower layer of thunderclouds that correspond to high-reflectivity regions can form strong electric fields producing gamma-ray glows. Also, these events are compared with a limited sample of nondetection cases, but no significant differences in meteorological conditions were found between detection and nondetection cases in the present study.

    DOI: 10.1029/2020GL091910

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    その他リンク: https://onlinelibrary.wiley.com/doi/full-xml/10.1029/2020GL091910

  41. Simulations of expected signal and background of gamma-ray sources by large field-of-view detectors aboard CubeSats

    Galgóczi, G; Rípa, J; Campana, R; Werner, N; Pál, A; Ohno, M; Mészáros, L; Mizuno, T; Tarcai, N; Torigoe, K; Uchida, N; Fukazawa, Y; Takahashi, H; Nakazawa, K; Hirade, N; Hirose, K; Hisadomi, S; Enoto, T; Odaka, H; Ichinohe, Y; Frei, Z; Kiss, L

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   7 巻 ( 2 )   2021年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    In recent years, the number of CubeSats (U-class spacecrafts) launched into space has increased exponentially marking the dawn of the nanosatellite technology. In general, these satellites have a much smaller mass budget compared to conventional scientific satellites, which limits shielding of scientific instruments against direct and indirect radiation in space. We present a simulation framework to quantify the signal in large field-of-view gamma-ray scintillation detectors of satellites induced by x-ray/gamma-ray transients, by taking into account the response of the detector. Furthermore, we quantify the signal induced by x-ray and particle background sources at a Low-Earth Orbit outside South Atlantic Anomaly and polar regions. Finally, we calculate the signal-to-noise ratio (SNR) taking into account different energy threshold levels. Our simulation can be used to optimize material composition and predict detectability of various astrophysical sources by CubeSats. We apply the developed simulation to a satellite belonging to a planned CAMELOT CubeSat constellation. This project mainly aims to detect short and long gamma-ray bursts (GRBs) and as a secondary science objective, to detect soft gamma-ray repeaters (SGRs) and terrestrial gamma-ray flashes (TGFs). The simulation includes a detailed computer-aided design model of the satellite to take into account the interaction of particles with the material of the satellite as accurately as possible. Results of our simulations predict that CubeSats can complement the large space observatories in high-energy astrophysics for observations of GRBs, SGRs, and TGFs. For the detectors planned to be on board the CAMELOT CubeSats, the simulations show that detections with SNR of at least 9 for median GRB and SGR fluxes are achievable.

    DOI: 10.1117/1.JATIS.7.2.028004

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  42. Annealing of proton radiation damages in Si-PM at room temperature 査読有り 国際共著

    Hirade, N; Takahashi, H; Uchida, N; Ohno, M; Torigoe, K; Fukazawa, Y; Mizuno, T; Matake, H; Hirose, K; Hisadomi, S; Nakazawa, K; Yamaoka, K; Werner, N; Rípa, J; Hatori, S; Kume, K; Mizushima, S

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   986 巻   頁: 164673 - 164673   2021年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER  

    We report the radiation damage results of two new types of Multi-Pixel Photon Counter (MPPC) under the 200 MeV proton beam, for cosmic gamma-ray observations with CubeSats. The new MPPCs, S13360-6050CS and S14160-6050HS, have recently become commercially available by Hamamatsu Photonics K.K. (HPK). After 100 rad irradiation, the dark current increased by a factor of similar to 100 and the threshold energy of gamma-ray detection by CsI scintillator increased, but S14160-6050HS was less degraded. We then confirmed the annealing effects of the dark current and threshold energy for both. The decrease rate of the dark current in both MPPCs were similar to those in the previous works. At 20 degrees C, the threshold energies of both MPPCs reduced by several tens of percent after irradiation, but below 0 degrees C, the threshold energy of S14160-6050HS was not significantly lowered. We also confirmed that annealing began before one month post-irradiation.

    DOI: 10.1016/j.nima.2020.164673

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  43. Detail Plans and Preparations for the Science Operations of the XRISM mission

    Terada, Y; Holland, M; Loewenstein, M; Tashiro, M; Takahashi, H; Nobukawa, M; Mizuno, T; Tamura, T; Uno, S; Watanabe, S; Baluta, C; Burns, L; Ebisawa, K; Eguchi, S; Fukazawa, Y; Hayashi, K; Iizuka, R; Katsuda, S; Kitaguchi, T; Kubota, A; Miller, E; Mukai, K; Nakashima, S; Nakazawa, K; Odaka, H; Ohno, M; Ota, N; Sato, R; Sugawara, Y; Shidatsu, M; Tamba, T; Tanimoto, A; Terashima, Y; Tsuboi, Y; Uchida, Y; Uchiyama, H; Yamauchi, S; Yaqoob, T

    SPACE TELESCOPES AND INSTRUMENTATION 2020: ULTRAVIOLET TO GAMMA RAY   11444 巻   2021年

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    記述言語:日本語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    The XRISM is the X-ray astronomical mission led by JAXA/NASA/ESA with international participation, plan to be launched in 2022 (Japanese fiscal year), to quickly recover the high-resolution X-ray spectroscopy of astrophysical objects using the micro-calorimeter array after the failure of Hitomi. To enhance the scientific outputs of the mission, the Science Operations Team (SOT) is structured independently from the instrument teams and the mission operation team (MOT). The responsibilities of the SOT are summarized into four categories: 1) Guest observer program and data distributions, 2) Distribution of the analyses software and calibration database, 3) Guest observer supporting activities, and 4) the performance verification and optimization (PVO) activities. Before constructing the Operations Concept of the XRISM mission, the lessons on the Science Operations learned from the past Japanese X-ray missions (ASCA, Suzaku, and Hitomi) are reviewed, and 16 kinds of lessons are identified by the above categories: lessons on the importance of avoiding nonpublic (“animal”) tools, coding quality of public tools both on the engineering viewpoint and the calibration accuracy, tight communications with instrument teams and operations team, well-defined task division between scientists and engineers etc. Among these lessons, a) importance of the early preparations of the operations from the ground stage, b) construction of the independent team for the Science Operations from the instrument developments, and c) operations with well-defined duties by appointed members are recognized as the key lessons for XRISM. Then, i) the task division between the Mission and Science Operations and ii) the subgroup structure within the XRISM team are defined in detail as the XRISM Operations Concept. Then, following the Operations Concept, the detail plan of the Science Operations is designed as follows. The Science Operations tasks are shared among Japan, US, and Europe operated by three centers, the Science Operations Center (SOC) at JAXA, the Science Data Center (SDC) at NASA, and European Space Astronomy Centre (ESAC) at ESA. The SOT is defined as a combination of the SOC and SDC; the SOC is designed to perform tasks close to the spacecraft operations, such as spacecraft planning of science targets, quick-look health checks, pre-pipeline data processing, etc., and the SDC covers the tasks on the data calibration processing (pipeline processing), maintenance of the analysis tools etc. The data-archive and users-support activities are planned to be covered both by the SOC and SDC. Finally, the details of the Science Operations tasks and the tools for the Science Operations are also described in this paper. This information would be helpful for a construction of Science Operations of future X-ray missions.

    DOI: 10.1117/12.2560861

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  44. New method to make a smooth surface on Carbon Fiber Reinforced Plastic (CFRP) substrate

    Awaki, H; Aida, N; Asakura, K; Hanaoka, M; Hattori, K; Ishibashi, K; Ishida, M; Ishikura, A; Maeda, Y; Matsumoto, H; Matsushita, Y; Mineta, T; Mitsuishi, I; Miyazawa, T; Nakaniwa, N; Nakazawa, K; Ode, Y; Oue, C; Sawagami, K; Sugita, S; Suzuki, H; Takahashi, H; Uchida, Y; Yamamoto, R; Yoshimoto, M

    SPACE TELESCOPES AND INSTRUMENTATION 2020: ULTRAVIOLET TO GAMMA RAY   11444 巻   2021年

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    記述言語:日本語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    CFRP is a composite material composed of carbon fiber and resin. CFRP is commonly applied to the aerospace industry which requires lightweight and intensity. Thanks to superior formability of CFRP, we can form shape of Wolter-1 optics, which consists of paraboloid and hyperboloid, to a monolithic substrate. Since the surface roughness of a CFRP substrate is a few µm, we have to make the smooth surface for reflecting X-rays on the CFRP substrate. We have developed a new method of shaping the reflective surface instead of the replica method used in lightweight X-ray mirrors such as Astro-H. In the new method, the reflective surface is formed by pasting thin sheet-glasses with 100 µm thick onto the CFRP substrate. The thin sheet-glass has a surface roughness about 0.4 nm as measured by Zygo. We fabricated a CFRP mirror pasting thin sheet-glasses, and then coated tungsten on the mirror in June 2020. The figure error (s) of the CFRP mirror was achieved to be about 1-2 µm by stacking the CFRP mirror on the housing module. X-ray imaging quality of the CFRP mirror was measured at Spring-8 in July 2020. The half-power diameter of the CFRP mirror was estimated to be about 150 arcsec, which was nearly equal to the prediction from a distribution of the slope error deduced from the surface profile. We describe a future plan to improve the image quality of the CFRP mirror.

    DOI: 10.1117/12.2561890

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  45. GRBAlpha: A 1U CubeSat mission for validating timing-based gamma-ray burst localization

    Pál, A; Ohno, M; Mészáros, L; Werner, N; Ripa, J; Frajt, M; Hirade, N; Hudec, J; Kapus, J; Koleda, M; Laszlo, R; Lipovsky, P; Matake, H; Smelko, M; Uchida, N; Csák, B; Enoto, T; Frei, Z; Fukazawa, Y; Galgóczi, G; Hirose, K; Hisadomi, S; Ichinohe, Y; Kiss, LL; Mizuno, T; Nakazawa, K; Odaka, H; Takahashi, H; Torigoe, K

    SPACE TELESCOPES AND INSTRUMENTATION 2020: ULTRAVIOLET TO GAMMA RAY   11444 巻   2021年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    GRBAlpha is a 1U CubeSat mission with an expected launch date in the first half of 2021. It carries a 75 × 75 × 5 mm CsI(Tl) scintillator, read out by a dual-channel multi-pixel photon counter (MPPC) setup, to detect gamma-ray bursts (GRBs). The GRB detector is an in-orbit demonstration for the detector system on the Cubesats Applied for MEasuring and LOcalising Transients (CAMELOT) mission. While GRBAlpha provides 1/8th of the expected effective area of CAMELOT, the comparison of the observed light curves with other existing GRB monitoring satellites will allow us to validate the core idea of CAMELOT, i.e. the feasibility of timing-based localization.

    DOI: 10.1117/12.2561351

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  46. Status of X-Ray Imaging and Spectroscopy Mission (XRISM)

    Tashiro, M; Maejima, H; Toda, K; Kelley, R; Reichenthal, L; Hartz, L; Petre, R; Williams, B; Guainazzi, M; Costantini, E; Fujimoto, R; Hayashida, K; Henegar-Leon, J; Holland, M; Ishisaki, Y; Kilbourne, C; Loewenstein, M; Matsushita, K; Mori, K; Okajima, T; Porter, FS; Sneiderman, G; Takei, Y; Terada, Y; Tomida, H; Yamaguchi, H; Watanabe, S; Akamatsu, H; Arai, Y; Audard, M; Awaki, H; Babyk, I; Bamba, A; Bando, N; Behar, E; Bialas, T; Boissay-Malaquin, R; Brenneman, L; Brown, G; Canavan, E; Chiao, M; Comber, B; Corrales, L; Cumbee, R; de Vries, C; den Herder, JW; Dercksen, J; Diaz-Trigo, M; DiPirro, M; Done, C; Dotani, T; Ebisawa, K; Eckart, M; Eckert, D; Eguchi, S; Enoto, T; Ezoe, Y; Ferrigno, C; Fujita, Y; Fukazawa, Y; Furuzawa, A; Gallo, L; Gorter, N; Grim, M; Gu, LY; Hagino, K; Hamaguchi, K; Hatsukade, I; Hawthorn, D; Hayashi, K; Hell, N; Hiraga, J; Hodges-Kluck, E; Horiuchi, T; Hornschemeier, A; Hoshino, A; Ichinohe, Y; Iga, S; Iizuka, R; Ishida, M; Ishihama, N; Ishikawa, K; Ishimura, K; Jaffe, T; Kaastra, J; Kallman, T; Kara, E; Katsuda, S; Kenyon, S; Kimball, M; Kitaguchi, T; Kitamoto, S; Kobayashi, S; Kobayashi, A; Kohmura, T; Kubota, A; Leutenegger, M; Li, MZ; Lockard, T; Maeda, Y; Markevitch, M; Martz, C; Matsumoto, H; Matsuzaki, K; McCammon, D; McLaughlin, B; McNamara, B; Miko, J; Miller, E; Miller, J; Minesugi, K; Mitani, S; Mitsuishi, I; Mizumoto, M; Mizuno, T; Mukai, K; Murakami, H; Mushotzky, R; Nakajima, H; Nakamura, H; Nakazawa, K; Natsukari, C; Nigo, K; Nishioka, Y; Nobukawa, K; Nobukawa, M; Noda, H; Odaka, H; Ogawa, M; Ohashi, T; Ohno, M; Ohta, M; Okamoto, A; Ota, N; Ozaki, M; Paltani, S; Plucinsky, P; Pottschmidt, K; Sampson, M; Sasaki, T; Sato, K; Sato, R; Sato, T; Sawada, M; Seta, H; Shibano, Y; Shida, M; Shidatsu, M; Shigeto, S; Shinozaki, K; Shirron, P; Simionescu, A; Smith, R; Someya, K; Soong, Y; Sugawara, K; Sugawara, Y; Szymkowiak, A; Takahashi, H; Takeshima, T; Tamagawa, T; Tamura, K; Tanaka, T; Tanimoto, A; Terashima, Y; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, T; Uchida, H; Uchida, Y; Uchiyama, H; Ueda, Y; Uno, S; Vink, J; Watanabe, T; Witthoeft, M; Wolfs, R; Yamada, S; Yamaoka, K; Yamasaki, N; Yamauchi, M; Yamauchi, S; Yanagase, K; Yaqoob, T; Yasuda, S; Yoshida, T; Yoshioka, N; Zhuravleva, I

    SPACE TELESCOPES AND INSTRUMENTATION 2020: ULTRAVIOLET TO GAMMA RAY   11444 巻   2021年

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    記述言語:日本語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    The X-Ray Imaging and Spectroscopy Mission (XRISM) is the successor to the 2016 Hitomi mission that ended prematurely. Like Hitomi, the primary science goals are to examine astrophysical problems with precise high-resolution X-ray spectroscopy. XRISM promises to discover new horizons in X-ray astronomy. XRISM carries a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly and a co-aligned X-ray CCD camera that covers the same energy band over a large field of view. XRISM utilizes Hitomi heritage, but all designs were reviewed. The attitude and orbit control system were improved in hardware and software. The number of star sensors were increased from two to three to improve coverage and robustness in onboard attitude determination and to obtain a wider field of view sun sensor. The fault detection, isolation, and reconfiguration (FDIR) system was carefully examined and reconfigured. Together with a planned increase of ground support stations, the survivability of the spacecraft is significantly improved.

    DOI: 10.1117/12.2565812

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  47. The XRISM Science Data Center: Optimizing the scientific return from a unique X-ray observatory

    Loewenstein, M; Hill, RS; Holland, MP; Miller, ED; Yaqoob, T; Doyle, TF; Hall, PL; Braun, E; Baluta, C; Mukai, K; Terada, Y; Tashiro, M; Takahashi, H; Nobukawa, M; Mizuno, T; Tamura, T; Uno, S; Watanabe, S; Ebisawa, K; Eguchi, S; Fukazawa, Y; Hayashi, K; Iizuka, R; Katsuda, S; Kitaguchi, T; Kubota, A; Nakashima, S; Nakazawa, K; Odaka, H; Ohno, M; Ota, N; Sato, R; Sugawara, Y; Shidatsu, M; Tamba, T; Tanimoto, A; Terashima, Y; Tsuboi, Y; Uchida, Y; Uchiyama, H; Yamauchi, S

    SPACE TELESCOPES AND INSTRUMENTATION 2020: ULTRAVIOLET TO GAMMA RAY   11444 巻   2021年

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    記述言語:日本語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    The X-Ray Imaging and Spectroscopy Mission, XRISM, is currently scheduled to launch in 2022 with the objective of building on the brief, but significant, successes of the ASTRO-H (Hitomi) mission in solving outstanding astrophysical questions using high resolution X-ray spectroscopy. The XRISM Science Operations Team (SOT) consists of the JAXA-led Science Operations Center (SOC) and NASA-led Science Data Center (SDC), which work together to optimize the scientific output from the Resolve high-resolution spectrometer and the Xtend wide-field imager through planning and scheduling of observations, processing and distribution of data, development and distribution of software tools and the calibration database (CaldB), support of ground and in-flight calibration, and support of XRISM users in their scientific investigations of the energetic universe. Here, we summarize the roles and responsibilities of the SDC and its current status and future plans. The Resolve instrument poses particular challenges due to its unprecedented combination of high spectral resolution and throughput, broad spectral coverage, and relatively small field-of-view and large pixel-size. We highlight those challenges and how they are being met.

    DOI: 10.1117/12.2560840

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  48. Solar Neutron Spectrometer Onboard a 3U CubeSat

    YAMAOKA Kazutaka, MATSUSHITA Koji, ITO Kazuya, NOBASHI Daiki, TAKAHASHI Hiromitsu, WATANABE Kyoko, TAJIMA Hiroyasu, MIYATA Kikuko, INAMORI Takaya, SASAI Yoshinori, KAWAHARA Hiroaki, PARK Ji Hyun, NAKAZAWA Kazuhiro, MASUDA Satoshi

    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, SPACE TECHNOLOGY JAPAN   19 巻 ( 3 ) 頁: 354 - 359   2021年

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    記述言語:英語   出版者・発行元:一般社団法人 日本航空宇宙学会  

    <p>Solar neutron observations are very important for understanding of nucleon acceleration mechanism in solar flares, but there are only a few tens of detection since the discovery in 1980. This is because solar neutron observations have been mainly carried out from not space but the ground with insufficient sensitivity. For microsatellite applications, we have designed very compact and high sensitive solar neutron and gamma-ray spectrometer utilizing a novel photo-sensor Silicon photo-multiplier. This paper describes concept, design and performance of our detector for micro/nanosatellite applications.</p>

    DOI: 10.2322/tastj.19.354

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  49. Current status of the x-ray mirror for the XL-Calibur experiment

    Kengo Hattori, Hironori Matsumoto, Quincy Abarr, Hisamitsu Awaki, Richard Bose, Dana Braun, Gianluigi De Geronimo, Paul Dowkontt, Teruaki Enoto, Manel Errando, Yasushi Fukazawa, Thomas A. Gadson, Victor Guarino, Shuichi Gunji, Kiyoshi Hayashida, Scott E. Heatwole, Shuntaro Ide, Manabu Ishida, Nirmal Iyer, Henric Krawczynski, Yoshitomo Maeda, Takuya Miyazawa, Hirofumi Noda, Takashi Okajima, Hiromitsu Takahashi, Keisuke Tamura, Hiroshi Tsunemi, Fabian Kislat, Mózsi Kiss, Takao Kitaguchi, Rakhee Kushwah, James Lanzi, Shaorui Li, Lindsey Lisalda, Tsunefumi Mizuno, Nozomi Nakaniwa, Mark Pearce, Zachary Peterson, Brian Rauch, David Stuchlik, Mai Takeo, Toru Tamagawa, Kazumi Uchida, Andrew T. West

    Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray     2020年12月

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE  

    DOI: 10.1117/12.2560928

  50. Satellite mission: PhoENiX (Physics of Energetic and Non-thermal plasmas in the X (= magnetic reconnection) region)

    Noriyuki Narukage, Mitsuo Oka, Yasushi Fukazawa, Keiichi Matsuzaki, Shin Watanabe, Taro Sakao, Kouichi Hagino, Ikuyuki Mitsuishi, Tsunefumi Mizuno, Iku Shinohara, Masumi Shimojo, Shinsuke Takasao, Hiroshi Tanabe, Munetaka Ueno, Tadayuki Takahashi, Takeshi Takashima, Masayuki Ohta

    Space Telescopes and Instrumentation 2020: Ultraviolet to Gamma Ray     2020年12月

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:SPIE  

    DOI: 10.1117/12.2561341

  51. Photonuclear Reactions in Lightning: 1. Verification and Modeling of Reaction and Propagation Processes

    Wada, Y; Enoto, T; Nakazawa, K; Odaka, H; Furuta, Y; Tsuchiya, H

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   125 巻 ( 20 )   2020年10月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Geophysical Research: Atmospheres  

    We report simulation results of photonuclear reactions in the atmosphere triggered by a downward terrestrial gamma ray flash in lightning. Possible channels of reactions in the atmosphere and their cross-sections are verified with the ENDF/B-VII.1 library. Monte Carlo simulations with two stages are then performed with the Geant4 framework. In the first stage, electrons following the relativistic runaway electron avalanche spectrum are produced in a mass model of the atmosphere, and production of photoneutrons and β+-decay nuclei is calculated based on the nuclear data library. In total 1 × 1013 neutrons and 4 × 1012 β+-decay nuclei are produced by 1018 energetic electrons above 1 MeV. In the second stage, propagation of the photoneutrons and positrons from the β+-decay nuclei in the previous stage is calculated. As a result, we model on-ground distributions of fluxes and energy spectra for neutrons, neutron-related gamma rays, and annihilation ones. The simulation model is to be compared with photonuclear events detected in low-charge-center winter thunderstorms.

    DOI: 10.1029/2020JD033193

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  52. Photonuclear Reactions in Lightning: 2. Comparison Between Observation and Simulation Model

    Wada, Y; Enoto, T; Nakazawa, K; Yuasa, T; Furuta, Y; Odaka, H; Makishima, K; Tsuchiya, H

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   125 巻 ( 20 )   2020年10月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Geophysical Research: Atmospheres  

    During a winter thunderstorm on 6 February 2017 in Japan, photonuclear reactions such as 14N(γ, n)13N were triggered by a downward terrestrial gamma-ray flash (TGF), as reported by Enoto et al. (2017, https://doi.org/10.1038/nature24630). In the present paper, we compare the observation with a simulation model of downward TGFs and subsequent photonuclear reactions constructed by the first paper of the series and Wada, Enoto, Nakazawa, et al. (2019, https://doi.org/10.1103/physrevlett.123.061103). The observation and model consist of three components: annihilation gamma rays from positrons produced by β+-decay nuclei, deexcitation gamma rays originating from neutron captures, and radiation doses by TGF photons. Each component of the observation is reproduced by the simulation model, and we constrain a relation between the number of avalanche electrons and their production altitude of the downward TGF. The constraints by three components match within an order of magnitude. The downward TGF is estimated to comprise (0.5–2.5) × 1019 avalanche electrons above 1 MeV produced at an altitude of 1.4–2.7 km. Despite differences in altitude, direction, and season, downward TGFs in winter thunderstorms are thought to have the same mechanism of electron acceleration and multiplication in lightning as TGFs observed by in-orbit satellites.

    DOI: 10.1029/2020JD033194

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  53. Origin of the in-orbit instrumental background of the Hard X-ray Imager onboard Hitomi

    Hagino, K; Odaka, H; Sato, G; Sato, T; Suzuki, H; Mizuno, T; Kawaharada, M; Ohno, M; Nakazawa, K; Kobayashi, SB; Murakami, H; Miyake, K; Asai, M; Koi, T; Madejski, G; Saito, S; Wright, DH; Enoto, T; Fukazawa, Y; Hayashi, K; Kataoka, J; Katsuta, J; Kokubun, M; Laurent, P; Lebrun, F; Limousin, O; Maier, D; Makishima, K; Mori, K; Nakamori, T; Nakano, T; Noda, H; Ohta, M; Sato, R; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Tanaka, T; Terada, Y; Uchiyama, H; Uchiyama, Y; Watanabe, S; Yamaoka, K; Yatsu, Y; Yuasa, T

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   6 巻 ( 4 )   2020年10月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    Understanding and reducing in-orbit instrumental backgrounds are essential to achieving high sensitivity in hard x-ray astronomical observations. The observational data of the Hard X-ray Imager (HXI) onboard the Hitomi satellite provide useful information on the background components due to its multilayer configuration with different atomic numbers: The HXI consists of a stack of four layers of Si (Z = 14) detectors and one layer of cadmium telluride (CdTe) (Z = 48, 52) detector surrounded by well-Type Bi4Ge3O12 active shields. Based on the observational data, the backgrounds of the top Si layer, the three underlying Si layers, and the CdTe layer are inferred to be dominated by different components, namely, low-energy electrons, albedo neutrons, and proton-induced radioactivation, respectively. Monte Carlo simulations of the in-orbit background of the HXI reproduce the observed background spectrum of each layer well, thereby quantitatively verifying the above hypothesis. In addition, we suggest the inclusion of an electron shield to reduce the background.

    DOI: 10.1117/1.JATIS.6.4.046003

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  54. Thundercloud Project: Exploring high-energy phenomena in thundercloud and lightning

    Yuasa, T; Wada, Y; Enoto, T; Furuta, Y; Tsuchiya, H; Hisadomi, S; Tsuji, Y; Okuda, K; Matsumoto, T; Nakazawa, K; Makishima, K; Miyake, S; Ikkatai, Y

    PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS   2020 巻 ( 10 )   2020年10月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Progress of Theoretical and Experimental Physics  

    We have designed, developed, and deployed a distributed sensor network to observe high-energy ionizing radiation, primarily gamma rays, from winter thunderclouds and lightning in coastal areas of Japan. Starting in 2015, we have installed a total of more than 15 ground-based detector systems in Ishikawa Prefecture and Niigata Prefecture, and accumulated 551 days of observation time in four winter seasons from late 2015 to early 2019. In this period, our system recorded 51 gamma-ray radiation events from thundercloud and lightning. Highlights of the science results obtained from this unprecedented amount of data include the discovery of photonuclear reaction in lightning which produces neutrons and positrons along with gamma rays, and deeper insights into the life cycle of a particle-acceleration and gamma-ray-emitting region in a thundercloud. The present paper reviews the objective, methodology, and results of our experiment, with an emphasis on its instrumentation.

    DOI: 10.1093/ptep/ptaa115

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  55. Implications of the mild gas motion found with <i>Hitomi</i> in the core of the Perseus cluster

    Gu, LY; Makishima, K; Matsumoto, R; Nakazawa, K; Shimasaku, K; Inada, N; Kodama, T; Xu, HG; Kawaharada, M

    ASTRONOMY & ASTROPHYSICS   638 巻   頁: A138 - A138   2020年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Astronomy and Astrophysics  

    Based mainly on X-ray observations, we study the interactions between the intracluster medium (ICM) in clusters of galaxies and their member galaxies. Through (magneto)hydrodynamic and gravitational channels, moving galaxies are expected to drag the ICM around them, and then transfer some fraction of their dynamical energies on cosmological timescales to the ICM. This hypothesis is in line with several observations, including the possible cosmological infall of galaxies toward the cluster center, found over redshifts of z? ∼? 1 to z? ∼? 0. Further assuming that the energy lost by these galaxies is first converted into ICM turbulence and then dissipated, this picture can explain the subsonic and uniform ICM turbulence, measured with Hitomi in the core region of the Perseus cluster. The scenario may also explain several other unanswered problems regarding clusters of galaxies, such as what prevents the ICM from underoing the expected radiative cooling, how the various mass components in nearby clusters have attained different radial distributions, and how a thermal stability is realized between hot and cool ICM components that co-exist around cD galaxies. This view is also considered to pertain to the general scenario of galaxy evolution, including their environmental effects.

    DOI: 10.1051/0004-6361/201936437

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  56. Photoneutron detection in lightning by gadolinium orthosilicate scintillators 査読有り

    Wada, Y; Nakazawa, K; Enoto, T; Furuta, Y; Yuasa, T; Makishima, K; Tsuchiya, H

    PHYSICAL REVIEW D   101 巻 ( 10 )   2020年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review D  

    During a winter thunderstorm on 24 November 2017, a downward terrestrial gamma-ray flash took place and triggered photonuclear reactions with atmospheric nitrogen and oxygen nuclei, coincident with a lightning discharge at the Kashiwazaki-Kariwa nuclear power station in Japan. We directly detected neutrons produced by the photonuclear reactions with gadolinium orthosilicate scintillation crystals installed at sea level. Two gadolinium isotopes included in the scintillation crystals, Gd155 and Gd157, have large cross sections of neutron captures to thermal neutrons such as Gd155(n,γ)Gd156 and Gd157(n,γ)Gd158. Deexcitation gamma rays from Gd156 and Gd158 are self-absorbed in the scintillation crystals, and make spectral-line features which can be distinguished from other non-neutron signals. The neutron burst lasted for ∼100 ms, and neutron fluences are estimated to be >52 and >31 neutrons cm-2 at two observation points inside the power station. Gadolinium orthosilicate scintillators work as valid detectors for thermal neutrons in lightning.

    DOI: 10.1103/PhysRevD.101.102007

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    その他リンク: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevD.101.102007/fulltext

  57. High Peak-Current Lightning Discharges Associated With Downward Terrestrial Gamma-Ray Flashes

    Wada, Y; Enoto, T; Nakamura, Y; Morimoto, T; Sato, M; Ushio, T; Nakazawa, K; Yuasa, T; Yonetoku, D; Sawano, T; Kamogawa, M; Sakai, H; Furuta, Y; Makishima, K; Tsuchiya, H

    JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES   125 巻 ( 4 )   2020年2月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Geophysical Research: Atmospheres  

    During 2017–2018 winter operation of the Gamma-Ray Observation of Winter Thunderclouds experiment in Japan, two downward terrestrial gamma-ray flashes (TGFs) that triggered atmospheric photonuclear reactions were detected. They took place during winter thunderstorms on 5 December 2017 and 9 January 2018 at Kanazawa, Ishikawa Prefecture, Japan. Each event coincided with an intracloud/intercloud discharge, which had a negative-polarity peak current higher than 150 kA. Their radio waveforms in the low-frequency band are categorized as a distinct lightning type called “energetic in-cloud pulse” (EIP). Negative-polarity EIPs have been previously suggested to be highly associated with downward TGFs, and the present observations provide evidence of the correlation between them for the first time. Furthermore, both of the downward TGFs followed “gamma-ray glows,” minute-lasting high-energy emissions from thunderclouds. It is suggested that the negative EIPs took place with downward propagating negative leaders or upward positive ones developed in highly electrified regions responsible for the gamma-ray glows.

    DOI: 10.1029/2019JD031730

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  58. The simulation framework of the timing-based localization for future all-sky gamma-ray observations with a fleet of Cubesats

    Ohno, M; Werner, N; Päl, A; Meszáros, L; Ichinohe, Y; Rípa, J; Topinka, M; Munz, F; Galgóczi, G; Fukazawa, Y; Mizuno, T; Takahashi, H; Uchida, N; Torigoe, K; Hirade, N; Hirose, K; Matake, H; Nakazawa, K; Hisadomi, S; Odaka, H; Enoto, T; Hudec, J; Kapus, J; Koleda, M; Laszlo, R

    X-RAY, OPTICAL, AND INFRARED DETECTORS FOR ASTRONOMY IX   11454 巻   2020年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    The timing-based localization, which utilize the triangulation principle with the different arrival time of gammaray photons, with a fleet of Cubesats is a unique and powerful solution for the future all-sky gamma-ray observation, which is a key for identification of the electromagnetic counterpart of the gravitational wave sources. The Cubesats Applied for MEasuring and Localising Transients (CAMELOT) mission is now being promoted by the Hungarian and Japanese collaboration with a basic concept of the nine Cubesats constellations in low earth orbit. The simulation framework for estimation of the localization capability has been developed including orbital parameters, an algorithm to estimate the expected observed profile of gamma-ray photons, finding the peak of the cross-correlation function, and a statistical method to find a best-fit position and its uncertainty. It is revealed that a degree-scale localization uncertainty can be achieved by the CAMELOT mission concept for bright short gamma-ray bursts, which could be covered by future large field of view ground-based telescopes. The new approach utilizing machine-learning approach is also investigated to make the procedure automated for the future large scale constellations. The trained neural network with 106 simulated light curves generated by the artificial short burst templates successfully predicts the time-delay of the real light curve and achieves a comparable performance to the cross-correlation algorithm with full automated procedures.

    DOI: 10.1117/12.2562253

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  59. 軟X線/硬X線の広帯域を高感度観測する次世代衛星 FORCE:サイエンスとミッション提案の現状

    中澤 知洋, 森 浩二, 鶴 剛, 上田 佳宏, 石田 学, 松本 浩典, 粟木 久光, 村上 弘志, 寺田 幸功, 久保田 あや, 馬場 彩, 小高 裕和, 谷津 陽一, 幸村 孝由, 萩野 浩一, 小林 翔悟, 内山 泰伸, 北山 哲, 高橋 忠幸, 渡辺 伸, 飯塚 亮, 山口 弘悦, 大橋 隆哉, 中嶋 大, 古澤 彰浩, 田中 孝明, 内田 裕之, 野田 博文, 常深 博, 伊藤 真之, 信川 正順, 信川 久実子, 太田 直美, 寺島 雄一, 深沢 泰司, 水野 恒史, 高橋 弘充, 大野 雅功, 武田 彩希, 岡島 崇, 他FORCE WG

    日本物理学会講演概要集   75.1 巻   頁: 523 - 523   2020年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.75.1.0_523

  60. A new possible accretion scenario for ultra-luminous X-ray sources 査読有り

    Kobayashi, SB; Nakazawa, K; Makishima, K

    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY   489 巻 ( 1 ) 頁: 366 - 384   2019年10月

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    記述言語:英語   出版者・発行元:Monthly Notices of the Royal Astronomical Society  

    Using archival data from Suzaku, XMM-Newton, and NuSTAR, nine representative ultra-luminous X-ray sources (ULXs) in nearby galaxies were studied. Their X-ray spectra were all reproduced with a multicolour disc emission model plus its Comptonization. However, the spectral shapes of individual sources changed systematically depending on the luminosity, and defined three typical spectral states. These states differ either in the ratio between the Comptonizing electron temperature and the innermost disc temperature, or in the product of Compton y-parameter and fraction of the Comptonized disc photons. The luminosity range at which a particular state emerges was found to scatter by a factor of up to 16 among the eight ULXs. By further assuming that the spectral state is uniquely determined by the Eddington ratio, the sample ULXs are inferred to exhibit a similar scatter in their masses. This gives a model-independent support to the interpretation of ULXs in terms of relatively massive black holes. None of the spectra showed noticeable local structures. Especially, no Fe K-shell absorption/emission lines were detected, with upper limits of 30-40 eV in equivalent width from the brightest three among the sample: NGC 1313 X-1, Holmberg IX X-1, and IC 342 X-1. These properties disfavour ordinary mass accretion from a massive companion star, and suggest direct Bondi-Hoyle accretion from dense parts of the interstellar medium.

    DOI: 10.1093/mnras/stz2139

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  61. Space gravitational-wave antennas DECIGO and B-DECIGO 査読有り

    Kawamura, S; Nakamura, T; Ando, M; Seto, N; Akutsu, T; Funaki, I; Ioka, K; Kanda, N; Kawano, I; Musha, M; Nakazawa, K; Sato, S; Takashima, T; Tanaka, T; Tsubono, K; Yokoyama, J; Agatsuma, K; Aoyanagi, K; Arai, K; Araya, A; Aritomi, N; Asada, H; Aso, Y; Chen, D; Chiba, T; Ebisuzaki, T; Eguchi, S; Ejiri, Y; Enoki, M; Eriguchi, Y; Fujimoto, MK; Fujita, R; Fukushima, M; Futamase, T; Gondo, R; Harada, T; Hashimoto, T; Hayama, K; Hikida, W; Himemoto, Y; Hirabayashi, H; Hiramatsu, T; Hong, FL; Horisawa, H; Hosokawa, M; Ichiki, K; Ikegami, T; Inoue, KT; Ishihara, H; Ishikawa, T; Ishizaki, H; Ito, H; Itoh, Y; Izumi, K; Kanemura, S; Kawashima, N; Kawazoe, F; Kishimoto, N; Kiuchi, K; Kobayashi, S; Kohri, K; Koizumi, H; Kojima, Y; Kokeyama, K; Kokuyama, W; Kotake, K; Kozai, Y; Kunimori, H; Kuninaka, H; Kuroda, K; Kuroyanagi, S; Maeda, K; Matsuhara, H; Matsumoto, N; Michimura, Y; Miyakawa, O; Miyamoto, U; Miyoki, S; Morimoto, MY; Morisawa, T; Moriwaki, S; Mukohyama, S; Nagano, S; Nakamura, K; Nakano, H; Nakao, K; Nakasuka, S; Nakayama, Y; Nishida, E; Nishizawa, A; Niwa, Y; Noumi, T; Obuchi, Y; Ohishi, N; Ohkawa, M; Okada, K; Okada, N; Okutomi, K; Oohara, K; Sago, N; Saijo, M; Saito, R; Sakagami, M; Sakai, S; Sakata, S; Sasaki, M; Sato, T; Shibata, M; Shibata, K; Shimo-oku, A; Shinkai, H; Shoda, A; Somiya, K; Sotani, H; Suemasa, A; Sugiyama, N; Suwa, Y; Suzuki, R; Tagoshi, H; Takahashi, F; Takahashi, K; Takahashi, K; Takahashi, R; Takahashi, R; Takahashi, H; Akiteru, T; Takano, T; Tanaka, N; Taniguchi, K; Taruya, A; Tashiro, H; Torii, Y; Toyoshima, M; Tsujikawa, S; Ueda, A; Ueda, K; Ushiba, T; Utashima, M; Wakabayashi, Y; Yagi, K; Yamamoto, K; Yamazaki, T; Yoo, CM; Yoshida, S; Yoshino, T

    INTERNATIONAL JOURNAL OF MODERN PHYSICS D   28 巻 ( 12 )   2019年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:International Journal of Modern Physics D  

    DECi-hertz Interferometer Gravitational-wave Observatory (DECIGO) is a future Japanese space gravitational-wave antenna. The most important objective of DECIGO, among various sciences to be aimed at, is to detect gravitational waves coming from the inflation of the universe. DECIGO consists of four clusters of spacecraft, and each cluster consists of three spacecraft with three Fabry-Perot Michelson interferometers. As a pathfinder mission of DECIGO, B-DECIGO will be launched, hopefully in the 2020s, to demonstrate technologies necessary for DECIGO as well as to lead to fruitful multimessenger astronomy. B-DECIGO is a small-scale or simpler version of DECIGO with the sensitivity slightly worse than that of DECIGO, yet good enough to provide frequent detection of gravitational waves.

    DOI: 10.1142/S0218271818450013

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  62. Downward Terrestrial Gamma-Ray Flash Observed in a Winter Thunderstorm 査読有り

    Wada, Y; Enoto, T; Nakazawa, K; Furuta, Y; Yuasa, T; Nakamura, Y; Morimoto, T; Matsumoto, T; Makishima, K; Tsuchiya, H

    PHYSICAL REVIEW LETTERS   123 巻 ( 6 ) 頁: 061103   2019年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Physical Review Letters  

    During a winter thunderstorm on 24 November 2017, a strong burst of gamma rays with energies up to ∼10 MeV was detected coincident with a lightning discharge, by scintillation detectors installed at the Kashiwazaki-Kariwa Nuclear Power Station at sea level in Japan. The burst had a subsecond duration, which is suggestive of photoneutron production. The leading part of the burst was resolved into four intense gamma-ray bunches, each coincident with a low-frequency radio pulse. These bunches were separated by 0.7-1.5 ms, with a duration of 1 ms each. Thus, the present burst may be considered as a "downward" terrestrial gamma-ray flash (TGF), which is analogous to upgoing TGFs observed from space. Although the scintillation detectors were heavily saturated by these bunches, the total dose associated with them was successfully measured by ionization chambers, employed by nine monitoring posts surrounding the power plant. From this information and Monte Carlo simulations, the present downward TGF is suggested to have taken place at an altitude of 2500±500 m, involving 8-4+8×1018 avalanche electrons with energies above 1 MeV. This number is comparable to those in upgoing TGFs.

    DOI: 10.1103/PhysRevLett.123.061103

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    PubMed

    その他リンク: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.123.061103/fulltext

  63. Estimation of the detected background by the future gamma ray transient mission CAMELOT 査読有り 国際共著

    Rípa, J; Galgóczi, G; Werner, N; Pál, A; Ohno, M; Mészáros, L; Mizuno, T; Tarcai, N; Torigoe, K; Uchida, N; Fukazawa, Y; Takahashi, H; Nakazawa, K; Hirade, N; Hirose, K; Hisadomi, S; Enoto, T; Odaka, H; Ichinohe, Y; Frei, Z; Kiss, L

    ASTRONOMISCHE NACHRICHTEN   340 巻 ( 7 ) 頁: 666 - 673   2019年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-V C H VERLAG GMBH  

    This study presents a background estimation for the CubeSats Applied for MEasuring and LOcalising Transients (CAMELOT), which is a proposed fleet of nanosatellites for the all-sky monitoring and timing-based localization of gamma ray transients with precise localization capability at low Earth orbits. CAMELOT will allow us to observe and precisely localize short gamma ray bursts (GRBs) associated with kilonovae, long GRBs associated with core-collapse massive stars, magnetar outbursts, terrestrial gamma ray flashes, and gamma ray counterparts to gravitational wave sources. A fleet of at least nine 3U CubeSats is proposed to be equipped with large and thin CsI(Tl) scintillators read out by multipixel photon counters (MPPC). A careful study of the radiation environment in space is necessary to optimize the detector casing, estimate the duty cycle due to the crossing of the South Atlantic Anomaly and polar regions, and minimize the effect of the radiation damage of MPPCs.

    DOI: 10.1002/asna.201913673

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  64. Spectral properties of gamma-ray bursts observed by the Suzaku wide-band all-sky monitor 査読有り

    Ohmori, N; Yamaoka, K; Yamauchi, M; Urata, Y; Ohno, M; Sugita, S; Hurley, K; Tashiro, MS; Fukazawa, Y; Iwakiri, W; Katsukura, D; Kokubun, M; Makishima, K; Murakami, S; Nakagawa, YE; Nakazawa, K; Odaka, K; Takahashi, K; Takahashi, T; Terada, Y

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   71 巻 ( 4 )   2019年8月

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    記述言語:日本語   出版者・発行元:Publications of the Astronomical Society of Japan  

    We have systematically studied the spectral properties of 302 localized gamma-ray bursts (GRBs) observed by the Suzaku wide-band all-sky monitor (WAM) from 2005 August to 2010 December. The energy spectra in the 100-5000 keV range integrated over the entire emission and the 1 s peak were fitted by three models: a single power law, a power law with an exponential cutoff (CPL), and the GRB Band function (GRB). Most of the burst spectra were well fitted by a single power law. The average photon index α was -2.11 and -1.73 for long and short bursts, respectively. For the CPL and GRB models, the low-energy and high-energy photon indices (α and β) for the entire emission spectra were consistent with previous measurements. The averages of the α and β were -0.90 and -2.65 for long-duration GRBs, while the average α was -0.55 and the β was not well constrained for short-duration GRBs. However, the average peak energy Epeak was 645 and 1286 keV for long- and short-duration GRBs respectively, which are higher than previous Fermi/GBM measurements (285 keV and 736 keV). The α and Epeak of the 1 s peak spectra were larger, i.e., the spectra were harder, than the total fluence spectra. Spectral simulations based on Fermi-GBM results suggest that the higher Epeaks measured by the Suzaku WAM could be due to detector selection bias, mainly caused by the limited energy range above 100 keV.

    DOI: 10.1093/pasj/psz054

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  65. Gamma-ray glow preceding downward terrestrial gamma-ray flash 査読有り

    Wada, Y; Enoto, T; Nakamura, Y; Furuta, Y; Yuasa, T; Nakazawa, K; Morimoto, T; Sato, M; Matsumoto, T; Yonetoku, D; Sawano, T; Sakai, H; Kamogawa, M; Ushio, T; Makishima, K; Tsuchiya, H

    COMMUNICATIONS PHYSICS   2 巻 ( 67 ) 頁: 1 - 9   2019年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Communications Physics  

    Two types of high-energy events have been detected from thunderstorms. One is “terrestrial gamma-ray flashes” (TGFs), sub-millisecond emissions coinciding with lightning discharges. The other is minute-lasting “gamma-ray glows”. Although both phenomena are thought to originate from relativistic runaway electron avalanches in strong electric fields, the connection between them is not well understood. Here we report unequivocal simultaneous detection of a gamma-ray glow termination and a downward TGF, observed from the ground. During a winter thunderstorm in Japan on 9 January 2018, our detectors caught a gamma-ray glow, which moved for ~100 s with ambient wind, and then abruptly ceased with a lightning discharge. Simultaneously, the detectors observed photonuclear reactions triggered by a downward TGF, whose radio pulse was located within ~1 km from where the glow ceased. It is suggested that the highly-electrified region producing the glow was related to the initiation of the downward TGF.

    DOI: 10.1038/s42005-019-0168-y

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  66. Event-selection technique for the multi-layer Si-CdTe Compton camera onboard <i>Hitomi</i>

    Ohno, M; Fukazawa, Y; Mizuno, T; Takahashi, H; Tanaka, Y; Katsuta, J; Kawano, T; Habata, S; Okada, C; Ohashi, N; Teramae, T; Tanaka, K; Takahashi, T; Kokubun, M; Watanabe, S; Sato, G; Sato, R; Ohta, M; Uchida, Y; Tamaru, R; Yoneda, H; Nakazawa, K; Murakami, H; Tajima, H; Yamaoka, K; Kinoshita, M; Hayashi, K; Kitaguchi, T; Odaka, H

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   924 巻   頁: 327 - 331   2019年4月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

    The soft gamma-ray detector (SGD) onboard Hitomi, which has a unique design concept, based on the combination of a ”narrow-field multi-layer semi-conductor Compton camera” and an active shielding, realizes astronomical observations in the 60−600 keV energy band with a high sensitivity. Development of optimum event selection criteria is essential for deriving the best observational performance of the SGD, but it is challenging because many parameters such as the detected photon energy, the Compton-scattering angle, and distance of each hit, among others, are non-linearly correlated. In this study, we propose a new method for distinguishing the signal from the background in the multi-parameter space utilizing a machine-learning approach. Our preliminary result, which uses both on-ground experimental data with good photon statistics and flight data with real in-orbit background and signal information, suggests that this approach might a good guide for an optimal event selection by the Compton camera.

    DOI: 10.1016/j.nima.2018.09.114

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  67. Performance study of a large CsI(Tl) scintillator with an MPPC readout for nanosatellites used to localize gamma-ray bursts 査読有り

    Torigoe, K; Fukazawa, Y; Galgóczi, G; Mizuno, T; Nakazawa, K; Ohno, M; Pál, A; Takahashi, H; Tanaka, K; Tarcai, N; Uchida, N; Werner, N; Enoto, T; Frei, Z; Ichinohe, Y; Kiss, L; Odaka, H; Rípa, J; Várhegyi, Z

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   924 巻   頁: 316 - 320   2019年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

    We are designing a fleet of nanosatellites to perform accurate position determinations of short-duration gamma-ray bursts by measuring arrival time differences. To achieve sufficient photon statistics to measure the arrival times precisely under the severe limitations of size, mass and power consumption, we propose the use of large-area CsI(Tl) scintillators which provide a high light output and the use of a small-sized multipixel photon counters (MPPC), a kind of SiPM, that have low power consumption. We plan to use one of the latest-model MPPCs provided by Hamamatsu Photonics, namely, S13360-6050CS, which has an active area of 6×6 mm2. We have compared the performance of two scintillators of different sizes (150×75×5 mm3 and 100×75×5 mm3); the bigger one is the maximum size that can be mounted on a three-unit satellite, according to CubeSat standards. We have found that the light yield of the bigger scintillator is lower than that of the smaller one, but the difference is only approximately 13%, and each has an energy threshold of ∼10 keV at 25∘C. We have tested one- and two-MPPC readout and confirmed the same energy thresholds. The light yield for the two-MPPC readout is 1.4 times as high as that for the one-MPPC readout. We have also examined the position dependence of the light yield by using radiation from a 241Am (59.5 keV) source, and confirmed that uniformity was improved, and energy resolution got better by ∼7% for two-MPPC readout.

    DOI: 10.1016/j.nima.2018.08.039

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  68. A NuSTAR study of the 55 ks hard X-ray pulse-phase modulation in the magnetar 4U 0142+61

    Makishima, K; Murakami, H; Enoto, T; Nakazawa, K

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   71 巻 ( 1 )   2019年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    Archival NuSTAR data of the magnetar 4U 0142+61, acquired in 2014 March for a total time span of 258 ks, were analyzed. This is to reconfirm the 55 ks modulation in the hard X-ray pulse phases of this source, found with a Suzaku observation in 2009 (Makishima et al.,2014, Phys. Rev. Lett., 112, 171102). Indeed, the 10-70 keV X-ray pulsation, detected with NuSTAR at 8.68917 s, was found to be also phase-modulated (at >98% confidence) at the same ∼55 ks period, or half that value. Furthermore, a brief analysis of another Suzaku data set of 4U 0142+61, acquired in 2013, reconfirmed the same 55 ks phase modulation in the 15-40 keV pulses. Thus, the hard X-ray pulse-phase modulation was detected with Suzaku (in 2009 and 2013) and NuSTAR (in 2014) at a consistent period. However, the modulation amplitude varied significantly; A ∼ 0.7 s with Suzaku (in 2009), A ∼ 1.2 s with Suzaku (in 2013), and A ∼ 0.17 s with NuSTAR. In addition, the phase modulation properties detected with NuSTAR differed considerably between the first 1/3 and the latter 2/3 of the observation. In energies below 10 keV, the pulse-phase modulation was not detected with either Suzaku or NuSTAR. These results reinforce the view of Makishima et al. (2014, Phys. Rev. Lett., 112, 171102); the neutron star in 4U 0142+61 keeps free precession, under a slight axial deformation due probably to ultra-high toroidal magnetic fields of ∼10 16 G. The wobbling angle of precession should remain constant, but the pulse-phase modulation amplitude varies on time scales of months to years, presumably as asymmetry of the hard X-ray emission pattern around the star's axis changes.

    DOI: 10.1093/pasj/psy129

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  69. Completeness of Cyclic Proofs for Symbolic Heaps with Inductive Definitions

    Tatsuta Makoto, Nakazawa Koji, Kimura Daisuke

    PROGRAMMING LANGUAGES AND SYSTEMS, APLAS 2019   11893 巻   頁: 367 - 387   2019年

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    出版者・発行元:Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)  

    DOI: 10.1007/978-3-030-34175-6_19

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  70. Gamma-ray observations at the coastal area of Japan Sea in winter seasons

    Tsuchiya H., Enoto T., Wada Y., Furuta Y., Nakazawa K., Yuasa T., Umemoto D., Makishima K.

    Proceedings of Science   358 巻   2019年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of Science  

    Since 2006, The Gamma Ray Observation of Winter Thunderclouds (GROWTH) collaboration has operated radiation measurement networks at the coastal area of Japan sea. The area is famous for its frequent occurrence of winter thunderstorms. We aims at elucidating how particles in lightning and thunderclouds are accelerated to relativistic energies. More than 10-years observations reveal that there are two types of radiation bursts associated with winter thunderstorms. One is a "long burst" or a "gamma-ray glow" lasting for a few tens of seconds to a few minutes. The other is a "short burst" in association with lightning. In order to expand the observational network, we have developed a small type of a radiation detector. In this paper, we focus on recent several findings obtained by the new detectors. One is a combination of a short burst and a long one, showing simultaneous detection of prompt gamma rays extending to ~10 MeV and the 511-keV annihilation ones. These gamma-ray signals demonstrate the occurrence of photonuclear reactions in lightning. Another is an event that a gamma-ray glow suddenly ceased just prior to lightning, suggesting a relation between lightning and the two types of radiation bursts. On the basis of these results, we discuss the production mechanism of gamma rays related to thunderstorms and the lightning initiation problem.

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  71. Solar neutron and gamma-ray detector for a 3U Cubesat

    Yamaoka K., Tajima H., Miyata K., Inamori T., Sasai Y., Kawahara H., Park J.H., Nakazawa K., Masuda S., Matsushita K., Itoh K., Nobashi D., Takahashi H., Watanabe K.

    Proceedings of Science   358 巻   2019年

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    記述言語:日本語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of Science  

    Solar neutron observations are very important on understanding of particle acceleration mechanism in the Sun. However, previous ground-based observations with large area telescope (~10 m2)at high latitude are not sensitive to solar neutrons due to attenuation in the earth atmosphere and roughly 10 detection since its discovery in 1980. From space, the SEDA-AP instrument with much smaller area (100 cm2) onboard the International Space Station (ISS) monitored solar neutrons including charged particles, and successfully detected more than 30 detection since its launch in 2009. Unfortunately the SEDA-AP operation was stopped on March 2018. To overcome situation for no mission dedicated for solar neutrons, we have designed and developed a solar neutron and gamma-ray detector for a 3U cubesat with a size of 30×10×10 cm. Actually we launched the 50-kg class ChubuSat-2 satellite for solar neutron observations on February 2016, and have now been adjusting it to a 3U cubesat application. The solar neutron and gamma-ray detector consists of multi-layered plastic scintillator bars, and GAGG(Ce) scintillator array, and both of them are read out with silicon photo-multipliers (Si PMs). More than 600 signals from Si PMs are processed by ASICs. In this paper, we will describe details of the detector and performance of its breadboard model (BBM).

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  72. Detection of polarized gamma-ray emission from the Crab nebula with the Hitomi Soft Gamma-ray Detector

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Nobukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemtsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A; Uchida, Y

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 6 )   2018年12月

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    記述言語:日本語   出版者・発行元:Publications of the Astronomical Society of Japan  

    We present the results from the Hitomi Soft Gamma-ray Detector (SGD) observation of the Crab nebula. The main part of SGD is a Compton camera, which in addition to being a spectrometer, is capable of measuring polarization of gamma-ray photons. The Crab nebula is one of the brightest X-ray/gamma-ray sources on the sky, and the only source from which polarized X-ray photons have been detected. SGD observed the Crab nebula during the initial test observation phase of Hitomi. We performed data analysis of the SGD observation, SGD background estimation, and SGD Monte Carlo simulations and successfully detected polarized gamma-ray emission from the Crab nebula with only about 5 ks exposure time. The obtained polarization fraction of the phase-integrated Crab emission (sum of pulsar and nebula emissions) is (22.1%±10.6%), and the polarization angle is 110°.7 + 13°.2/-13°.0 in the energy range of 60.160 keV (the errors correspond to the 1 σ deviation). The confidence level of the polarization detection was 99.3%. The polarization angle measured by SGD is about one sigma deviation with the projected spin axis of the pulsar, 124°.0 ± 0°.0.1.

    DOI: 10.1093/pasj/psy118

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  73. Termination of Electron Acceleration in Thundercloud by Intracloud/Intercloud Discharge 査読有り

    Wada, Y; Bowers, GS; Enoto, T; Kamogawa, M; Nakamura, Y; Morimoto, T; Smith, DM; Furuta, Y; Nakazawa, K; Yuasa, T; Matsuki, A; Kubo, M; Tamagawa, T; Makishima, K; Tsuchiya, H

    GEOPHYSICAL RESEARCH LETTERS   45 巻 ( 11 ) 頁: 5700 - 5707   2018年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Geophysical Research Letters  

    An on-ground observation program for high energy atmospheric phenomena in<br />
    winter thunderstorms along Japan Sea has been performed via measurements of<br />
    gamma-ray radiation, atmospheric electric field and low-frequency radio band.<br />
    On February 11, 2017, the radiation detectors recorded gamma-ray emission<br />
    lasting for 75 sec. The gamma-ray spectrum extended up to 20 MeV and was<br />
    reproduced by a cutoff power-law model with a photon index of<br />
    $1.36^{+0.03}_{-0.04}$, being consistent with a Bremsstrahlung radiation from a<br />
    thundercloud (as known as a gamma-ray glow and a thunderstorm ground<br />
    enhancement). Then the gamma-ray glow was abruptly terminated with a nearby<br />
    lightning discharge. The low-frequency radio monitors, installed $\sim$50 km<br />
    away from the gamma-ray observation site recorded leader development of an<br />
    intra/inter-cloud discharge spreading over $\sim$60 km area with a $\sim$300 ms<br />
    duration. The timing of the gamma-ray termination coincided with the moment<br />
    when the leader development of the intra/inter-cloud discharge passed 0.7 km<br />
    horizontally away from the radiation monitors. The intra/inter-cloud discharge<br />
    started $\sim$15 km away from the gamma-ray observation site. Therefore, the<br />
    glow was terminated by the leader development, while it did not trigger the<br />
    lightning discharge in the present case.

    DOI: 10.1029/2018GL077784

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    arXiv

  74. ATCA 16 cm observation of CIZA J1358.9-4750: Implication of merger stage and constraint on non-thermal properties 査読有り

    Akahori, T; Kato, Y; Nakazawa, K; Ozawa, T; Gu, LY; Takizawa, M; Fujita, Y; Nakanishi, H; Okabe, N; Makishima, K

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 3 )   2018年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    We report the Australia Telescope Compact Array 16 cm observation of CIZA J1358.9-4750. Recent X-ray studies imply that this galaxy cluster is composed of merging, binary clusters. Using the EW367 configuration, we found no significant diffuse radio emission in and around the cluster. An upper limit of the total radio power at 1.4 GHz is ∼1.1 × 1022 W Hz-1 in 30 square arcminutes, which is a typical size for radio relics. It is known that an empirical relation holds between the total radio power and X-ray luminosity of the host cluster. The upper limit is about one order of magnitude lower than the power expected from the relation. Very young (∼70 Myr) shocks with low Mach numbers (∼1.3), which are often seen at an early stage of merger simulations, are suggested by the previous X-ray observation. The shocks may generate cosmic-ray electrons with a steep energy spectrum, which is consistent with non-detection of bright (>1023 W Hz-1) relic in this 16 cm band observation. Based on the assumption of energy equipartition, the upper limit gives a magnetic field strength of below 0.68f(Dlos/1 Mpc)-1(γmin/200)-1 μG, where f is the cosmic-ray total energy density over the cosmic-ray electron energy density, Dlos is the depth of the shock wave along the sightline, and min is the lower cutoff Lorentz factor of the cosmic-ray electron energy spectrum.

    DOI: 10.1093/pasj/psy042

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  75. Multiwavelength study of X-ray luminous clusters in the Hyper Suprime-Cam Subaru Strategic Program S16A field (vol 70, S22, 2018) 査読有り

    Miyaoka, K; Okabe, N; Kitaguchi, T; Oguri, M; Fukazawa, Y; Mandelbaum, R; Medezinski, E; Babazaki, Y; Nishizawa, AJ; Hamana, T; Lin, YT; Akamatsu, H; Chiu, IN; Fujita, Y; Ichinohe, Y; Komiyama, Y; Sasaki, T; Takizawa, M; Ueda, S; Umetsu, K; Coupon, J; Hikage, C; Hoshino, A; Leauthaud, A; Matsushita, K; Mitsuishi, I; Miyatake, H; Miyazaki, S; More, S; Nakazawa, K; Ota, N; Sato, K; Spergel, D; Tamura, T; Tanaka, M; Tanaka, MM; Utsumi, Y

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 3 )   2018年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    In the published version of this article, (Publications of the Astronomical Society of Japan, Volume 70, Issue SP1, 2018, S22, first published online 21 December 2017, doi: 10.1093/pasj/psx132), the following error appears: The caption for figure 3 appears under figure 4 and the caption for figure 4 appears under figure 3. The publisher apologises for the error.(Figure Persenetd).

    DOI: 10.1093/pasj/psy024

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  76. Hitomi X-ray observation of the pulsar wind nebula G21.5-0.9 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Nobukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemtsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Uno, S; Ueda, Y; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A; Sato, T; Nakaniwa, N; Murakami, H; Guest, B

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 3 )   2018年6月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.5-0.9, whose emission is dominated by the pulsar wind nebula (PWN) contribution. The X-ray spectra in the 0.8-80 keV range obtained with the Soft X-ray Spectrometer (SXS), Soft X-ray Imager, and Hard X-ray Imager (HXI) show a significant break in the continuum as previously found with the NuSTAR observation. After taking into account all known emissions from the SNR other than the PWN itself, we find that the Hitomi spectra can be fitted with a broken power law with photon indices of 1 = 1.74 ± 0.02 and 2 = 2.14 ± 0.01 below and above the break at 7.1 ± 0.3 keV, which is significantly lower than the NuSTAR result (∼9.0 keV). The spectral break cannot be reproduced by time-dependent particle injection one-zone spectral energy distribution models, which strongly indicates that a more complex emission model is needed, as suggested by recent theoretical models. We also search for narrow emission or absorption lines with the SXS, and perform a timing analysis of PSR J1833-1034 with the HXI and the Soft Gamma-ray Detector. No significant pulsation is found from the pulsar. However, unexpectedly, narrow absorption line features are detected in the SXS data at 4.2345 keV and 9.296 keV with a significance of 3.65 s. While the origin of these features is not understood, their mere detection opens up a new field of research and was only possible with the high resolution, sensitivity, and ability to measure extended sources provided by an X-ray microcalorimeter.

    DOI: 10.1093/pasj/psy027

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  77. Modeling of proton-induced radioactivation background in hard X-ray telescopes: Geant4-based simulation and its demonstration by <i>Hitomi</i>'s measurement in a low Earth orbit 査読有り

    Odaka, H; Asai, M; Hagino, K; Koi, T; Madejski, G; Mizuno, T; Ohno, M; Saito, S; Sato, T; Wright, DH; Enoto, T; Fukazawa, Y; Hayashi, K; Kataoka, J; Katsuta, J; Kawaharada, M; Kobayashi, SB; Kokubun, M; Laurent, P; Lebrun, F; Limousin, O; Maier, D; Makishima, K; Mimura, T; Miyake, K; Mori, K; Murakami, H; Nakamori, T; Nakano, T; Nakazawa, K; Noda, H; Ohta, M; Ozaki, M; Sato, G; Sato, R; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Tanaka, T; Tanaka, Y; Terada, Y; Uchiyama, H; Uchiyama, Y; Watanabe, S; Yamaoka, K; Yasuda, T; Yatsu, Y; Yuasa, T; Zoglauer, A

    NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT   891 巻   頁: 92 - 105   2018年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment  

    Hard X-ray astronomical observatories in orbit suffer from a significant amount of background due to radioactivation induced by cosmic-ray protons and/or geomagnetically trapped protons. Within the framework of a full Monte Carlo simulation, we present modeling of in-orbit instrumental background which is dominated by radioactivation. To reduce the computation time required by straightforward simulations of delayed emissions from activated isotopes, we insert a semi-analytical calculation that converts production probabilities of radioactive isotopes by interaction of the primary protons into decay rates at measurement time of all secondary isotopes. Therefore, our simulation method is separated into three steps: (1) simulation of isotope production, (2) semi-analytical conversion to decay rates, and (3) simulation of decays of the isotopes at measurement time. This method is verified by a simple setup that has a CdTe semiconductor detector, and shows a 100-fold improvement in efficiency over the straightforward simulation. To demonstrate its experimental performance, the simulation framework was tested against data measured with a CdTe sensor in the Hard X-ray Imager onboard the Hitomi X-ray Astronomy Satellite, which was put into a low Earth orbit with an altitude of 570 km and an inclination of 31°, and thus experienced a large amount of irradiation from geomagnetically trapped protons during its passages through the South Atlantic Anomaly. The simulation is able to treat full histories of the proton irradiation and multiple measurement windows. The simulation results agree very well with the measured data, showing that the measured background is well described by the combination of proton-induced radioactivation of the CdTe detector itself and thick Bi4Ge3O12 scintillator shields, leakage of cosmic X-ray background and albedo gamma-ray radiation, and emissions from naturally contaminated isotopes in the detector system.

    DOI: 10.1016/j.nima.2018.02.071

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  78. Design and performance of Soft Gamma-ray Detector onboard the Hitomi (ASTRO-H) satellite 査読有り

    Tajima, H; Watanabe, S; Fukazawa, Y; Blandford, R; Enoto, T; Goldwurm, A; Hagino, K; Hayashi, K; Ichinohe, Y; Kataoka, J; Katsuta, J; Kitaguchi, T; Kokubun, M; Laurent, P; Lebrun, F; Limousin, O; Madejski, GM; Makishima, K; Mizuno, T; Mori, K; Nakamori, T; Nakano, T; Nakazawa, K; Noda, H; Odaka, H; Ohno, M; Ohta, M; Saito, S; Sato, G; Sato, R; Takeda, S; Takahashi, H; Takahashi, T; Tanaka, T; Tanaka, Y; Terada, Y; Uchiyama, H; Uchiyama, Y; Yamaoka, K; Yatsu, Y; Yonetoku, D; Yuasao, T

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   4 巻 ( 2 )   2018年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    Hitomi (ASTRO-H) was the sixth Japanese X-ray satellite that carried instruments with exquisite energy resolution of <7 eV and broad energy coverage of 0.3 to 600 keV. The Soft Gamma-ray Detector (SGD) was the Hitomi instrument that observed the highest energy band (60 to 600 keV). The SGD design achieves a low background level by combining active shields and Compton cameras where Compton kinematics is utilized to reject backgrounds coming from outside of the field of view. A compact and highly efficient Compton camera is realized using a combination of silicon and cadmium telluride semiconductor sensors with a good energy resolution. Compton kinematics also carries information for gamma-ray polarization, making the SGD an excellent polarimeter. Following several years of development, the satellite was successfully launched on February 17, 2016. After proper functionality of the SGD components were verified, the nominal observation mode was initiated on March 24, 2016. The SGD observed the Crab Nebula for approximately two hours before the spacecraft ceased to function on March 26, 2016. We present concepts of the SGD design followed by detailed description of the instrument and its performance measured on ground and in orbit.

    DOI: 10.1117/1.JATIS.4.2.021411

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  79. In-orbit performance and calibration of the Hard X-ray Imager onboard Hitomi (ASTRO-H)

    Hagino K.

    Journal of Astronomical Telescopes, Instruments, and Systems   4 巻 ( 2 )   2018年4月

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    出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    DOI: 10.1117/1.JATIS.4.2.021409

    Scopus

  80. Hitomi (ASTRO-H) X-ray Astronomy Satellite 査読有り

    Takahashi, T; Kokubun, M; Mitsuda, K; Kelley, RL; Ohashi, T; Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Anabuki, N; Angelini, L; Arnaud, K; Asai, M; Audard, M; Awaki, H; Axelsson, M; Azzarello, P; Baluta, C; Bamba, A; Bando, N; Bautz, MW; Bialas, T; Blandford, R; Boyce, K; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Canavan, E; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; Dell, SO; DiPirro, M; Done, C; Dotani, T; Doty, J; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Funk, S; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Gilmore, K; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haas, D; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, T; Hayashi, K; Hayashida, K; den Herder, JW; Hiraga, JS; Hirose, K; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishibashi, K; Ishida, M; Ishikawa, K; Ishimura, K; Ishisaki, Y; Itoh, M; Iwai, M; Iwata, N; Iyomoto, N; Jewell, C; Kaastra, J; Kallman, T; Kamae, T; Kara, E; Kataoka, J; Katsuda, S; Katsuta, J; Kawaharada, M; Kawai, N; Kawano, T; Kawasaki, S; Khangulyan, D; Kilbourne, CA; Kimball, M; King, A; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Konami, S; Kosaka, T; Koujelev, A; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Masters, C; Matsumoto, H; Matsushita, K; McCammon, D; Mcguinness, D; McNamara, BR; Mehdipour, M; Miko, J; Miller, ED; Miller, JM; Mineshige, S; Minesugi, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Moroso, F; Moseley, H; Muench, T; Mukai, K; Murakami, H; Murakami, T; Mushotzky, RF; Nagano, H; Nagino, R; Nakagawa, T; Nakajima, H; Nakamori, T; Nakano, T; Nakashima, S; Nakazawa, K; Namba, Y; Natsukari, C; Nishioka, Y; Nobukawa, KK; Nobukawa, M; Noda, H; Nomachi, M; Odaka, H; Ogawa, H; Ogawa, M; Ogi, K; Ohno, M; Ohta, M; Okajima, T; Okamoto, A; Okazaki, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Parmar, A; Petre, R; Pinto, C; de Plaa, J; Pohl, M; Pontius, J; Porter, FS; Pottschmidt, K; Ramsey, B; Reynolds, C; Russell, H; Safi-Harb, S; Saito, S; Sakai, K; Sakai, S; Sameshima, H; Sasaki, T; Sato, G; Sato, K; Sato, R; Sato, Y; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shibano, Y; Shida, M; Shidatsu, M; Shimada, T; Shinozaki, K; Shirron, P; Simionescu, A; Simmons, C; Smith, RK; Sneiderman, G; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Sugita, H; Szymkowiak, A; Tajima, H; Takahashi, H; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tamura, K; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Ueno, S; Uno, S; Urry, CM; Ursino, E; de Vries, CP; Wada, A; Watanabe, S; Watanabe, T; Werner, N; Wik, DR; Wilkins, DR; Williams, BJ; Yamada, S; Yamada, T; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Yoshida, A; Yuasa, T; Zhuravleva, I; Zoghbi, A

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   4 巻 ( 2 )   2018年4月

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    記述言語:日本語   出版者・発行元:Journal of Astronomical Telescopes, Instruments, and Systems  

    The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.

    DOI: 10.1117/1.JATIS.4.2.021402

    Web of Science

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  81. The Hitomi X-Ray Observatory, Part 2 査読有り

    Kelley Richard L, Nakazawa Kazuhiro

    JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS   4 巻 ( 2 )   2018年4月

  82. Atmospheric gas dynamics in the Perseus cluster observed with Hitomi

    Aharonia F., Aharonian F., Akamatsu H., Akimoto F., Allen S.W., Angelini L., Audard M., Awaki H., Axelsson M., Bamba A., Bautz M.W., Blandford R., Brenneman L.W., Brown G.V., Bulbul E., Cackett E.M., Canning R.E.A., Chernyakova M., Chiao M.P., Coppi P.S., Costantini E., De Plaa J., De Vries C.P., Den Herder J.W., Done C., Dotani T., Ebisawa K., Eckart M.E., Enoto T., Ezoe Y., Fabian A.C., Ferrigno C., Foster A.R., Fujimoto R., Fukazawa Y., Furuzawa A., Galeazzi M., Gallo L.C., Gandhi P., Giustini M., Goldwurm A., Gu L., Guainazzi M., Haba Y., Hagino K., Hamaguchi K., Harrus I.M., Hatsukade I., Hayashi K., Hayashi T., Hayashi T., Hayashida K., Hiraga J.S., Hornschemeier A., Hoshino A., Hughes J.P., Ichinohe Y., Iizuka R., Inoue H., Inoue S., Inoue Y., Ishida M., Ishikawa K., Ishisaki Y., Iwai M., Kaastra J., Kallman T., Kamae T., Kataoka J., Katsuda S., Kawai N., Kelley R.L., Kilbourne C.A., Kitaguchi T., Kitamoto S., Kitayama T., Kohmura T., Kokubun M., Koyama K., Koyama S., Kretschmar P., Krimm H.A., Kubota A., Kunieda H., Laurent P., Lee S.H., Leutenegger M.A., Limousin O., Loewenstein M., Long K.S., Lumb D., Madejski G., Maeda Y., Maier D., Makishima K., Markevitch M., Matsumoto H., Matsushita K., Mccammon D., Mcnamara B.R.

    Publications of the Astronomical Society of Japan   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   出版者・発行元:Publications of the Astronomical Society of Japan  

    Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100kpc of the Perseus cluster using observations obtained with the Hitomi satellite. After correcting for the point spread function of the telescope and using optically thin emission lines, we find that the line-of-sight velocity dispersion of the hot gas is remarkably low and mostly uniform. The velocity dispersion reaches a maxima of approximately 200 km s-1 toward the central active galactic nucleus (AGN) and toward the AGN inflated northwestern "ghost" bubble. Elsewhere within the observed region, the velocity dispersion appears constant around 100 km s-1. We also detect a velocity gradient with a 100 km s-1 amplitude across the cluster core, consistent with large-scale sloshing of the core gas. If the observed gas motions are isotropic, the kinetic pressure support is less than 10% of the thermal pressure support in the cluster core. The well-resolved, optically thin emission lines have Gaussian shapes, indicating that the turbulent driving scale is likely below 100 kpc, which is consistent with the size of the AGN jet inflated bubbles. We also report the first measurement of the ion temperature in the intracluster medium, which we find to be consistent with the electron temperature. In addition, we present a new measurement of the redshift of the brightest cluster galaxy NGC 1275.

    Scopus

  83. Hitomi X-ray studies of giant radio pulses from the Crab pulsar

    Aharonian F.

    Publications of the Astronomical Society of Japan   70 巻 ( 2 )   2018年3月

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    出版者・発行元:Publications of the Astronomical Society of Japan  

    Scopus

  84. Atmospheric gas dynamics in the Perseus cluster observed with Hitomi 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Canning, REA; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, S; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumr, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Norukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, K; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Wang, QHS; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1093/pasj/psx138

    Web of Science

  85. Search for thermal X-ray features from the Crab nebula with the Hitomi soft X-ray spectrometer 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguch, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Nobukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sato, T; Sawada, M; Schartel, N; Serlemtsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A; Tominaga, N; Moriya, TJ

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    The Crab nebula originated from a core-collapse supernova (SN) explosion observed in 1054AD. When viewed as a supernova remnant (SNR), it has an anomalously low observed ejecta mass and kinetic energy for an Fe-core-collapse SN. Intensive searches have been made for a massive shell that solves this discrepancy, but none has been detected. An alternative idea is that SN 1054 is an electron-capture (EC) explosion with a lower explosion energy by an order of magnitude than Fe-core-collapse SNe. X-ray imaging searches were performed for the plasma emission from the shell in the Crab outskirts to set a stringent upper limit on the X-ray emitting mass. However, the extreme brightness of the source hampers access to its vicinity. We thus employed spectroscopic technique using the X-ray micro-calorimeter on board the Hitomi satellite. By exploiting its superb energy resolution, we set an upper limit for emission or absorption features from as yet undetected thermal plasma in the 2-12keV range. We also re-evaluated the existing Chandra and XMM-Newton data. By assembling these results, a new upper limit was obtained for the X-ray plasma mass of < 1 M⊙ for a wide range of assumed shell radius, size, and plasma temperature values both in and out of collisional equilibrium. To compare with the observation, we further performed hydrodynamic simulations of the Crab SNR for two SN models (Fe-core versus EC) under two SN environments (uniform interstellar medium versus progenitor wind). We found that the observed mass limit can be compatible with both SN models if the SN environment has a low density of < 0.03 cm-3 (Fe core) or < 0.1 cm-3 (EC) for the uniform density, or a progenitor wind density somewhat less than that provided by a mass loss rate of 10-5M⊙ yr-1 at 20 km s-1for the wind environment.

    DOI: 10.1093/pasj/psx072

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  86. Measurements of resonant scattering in the Perseus Cluster core with Hitomi SXS 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furukawa, M; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, OO; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Norukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ogorzalek, A; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    Thanks to its high spectral resolution (∼5 eV at 6 keV), the Soft X-ray Spectrometer (SXS) on board Hitomi enables us to measure the detailed structure of spatially resolved emission lines from highly ionized ions in galaxy clusters for the first time. In this series of papers, using the SXS we have measured the velocities of gas motions, metallicities and the multi-temperature structure of the gas in the core of the Perseus Cluster. Here, we show that when inferring physical properties from line emissivities in systems like Perseus, the resonant scattering effect should be taken into account. In the Hitomi waveband, resonant scattering mostly affects the Fe XXV Heα line (w)-the strongest line in the spectrum. The flux measured by Hitomi in this line is suppressed by a factor of ∼1.3 in the inner ∼30 kpc, compared to predictions for an optically thin plasma; the suppression decreases with the distance from the center. The w line also appears slightly broader than other lines from the same ion. The observed distortions of the w line flux, shape, and distance dependence are all consistent with the expected effect of the resonant scattering in the Perseus core. By measuring the ratio of fluxes in optically thick (w) and thin (Fe XXV forbidden, Heβ, Lyα) lines, and comparing these ratios with predictions from Monte Carlo radiative transfer simulations, the velocities of gas motions have been obtained. The results are consistent with the direct measurements of gas velocities from line broadening described elsewhere in this series, although the systematic and statistical uncertainties remain significant. Further improvements in the predictions of line emissivities in plasma models, and deeper observations with future X-ray missions offering similar or better capabilities to the Hitomi SXS, will enable resonant scattering measurements to provide powerful constraints on the amplitude and anisotropy of cluster gas motions.

    DOI: 10.1093/pasj/psx127

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  87. Hitomi X-ray studies of giant radio pulses from the Crab pulsar 査読有り

    Aharonian Felix, Akamatsu Hiroki, Akimoto Fumie, Allen Steven W., Angelini Lorella, Audard Marc, Awaki Hisamitsu, Axelsson Magnus, Bamba Aya, Bautz Marshall W., Blandford Roger, Brenneman Laura W., Brown Gregory V, Bulbul Esra, Cackett Edward M., Chernyakova Maria, Chiao Meng P., Coppi Paolo S., Costantini Elisa, De Plaa Jelle, De Vries Cor P., Den Herder Jan-Willem, Done Chris, Dotani Tadayasu, Ebisawa Ken, Eckart Megan E., Enoto Teruaki, Ezoe Yuichiro, Fabian Andrew C., Ferrigno Carlo, Foster Adam R., Fujimoto Ryuichi, Fukazawa Yasushi, Furuzawa Akihiro, Galeazzi Massimiliano, Gallo Luigi C., Gandhi Poshak, Giustini Margherita, Goldwurm Andrea, Gu Liyi, Guainazzi Matteo, Haba Yoshito, Hagino Kouichi, Hamaguchi Kenji, Harrus Ilana M., Hatsukade Isamu, Hayashi Katsuhiro, Hayashi Takayuki, Hayashida Kiyoshi, Hiraga Junko S., Hornschemeier Ann, Hoshino Akio, Hughes John P., Ichinohe Yuto, Iizuka Ryo, Inoue Hajime, Inoue Yoshiyuki, Ishida Manabu, Ishikawa Kumi, Ishisaki Yoshitaka, Iwai Masachika, Kaastra Jelle, Kallman Tim, Kamae Tsuneyoshi, Kataoka Jun, Katsuda Satoru, Kawai Nobuyuki, Kelley Richard L., Kilbourne Caroline A., Kitaguchi Takao, Kitamoto Shunji, Kitayama Tetsu, Kohmura Takayoshi, Kokubun Motohide, Koyama Katsuji, Koyama Shu, Kretschmar Peter, Krimm Hans A., Kubota Aya, Kunieda Hideyo, Laurent Philippe, Lee Shiu-Hang, Leutenegger Maurice A., Limousin Olivier O., Loewenstein Michael, Long Knox S., Lumb David, Madejski Greg, Maeda Yoshitomo, Maier Daniel, Makishima Kazuo, Markevitch Maxim, Matsumoto Hironori, Matsushita Kyoko, McCammon Dan, McNamara Brian R., Mehdipour Missagh, Miller Eric D., Miller Jon M., Mineshige Shin, Mitsuda Kazuhisa, Mitsuishi Ikuyuki, Miyazawa Takuya, Mizuno Tsunefumi, Mori Hideyuki, Mori Koji, Mukai Koji, Murakami Hiroshi, Mushotzky Richard F., Nakagawa Takao, Nakajima Hiroshi, Nakamori Takeshi, Nakashima Shinya, Nakazawa Kazuhiro, Nobukawa Kumiko K., Nobukawa Masayoshi, Noda Hirofumi, Odaka Hirokazu, Ohashi Takaya, Ohno Masanori, Okajima Takashi, Oshimizu Kenya, Ota Naomi, Ozaki Masanobu, Paerels Frits, Paltani Stephane, Petre Robert, Pinto Ciro, Porter Frederick S., Pottschmidt Katja, Reynolds Christopher S., Safi-Harb Samar, Saito Shinya, Sakai Kazuhiro, Sasaki Toru, Sato Goro, Sato Kosuke, Sato Rie, Sawada Makoto, Schartel Norbert, Serlemtsos Peter J., Seta Hiromi, Shidatsu Megumi, Simionescu Aurora, Smith Randall K., Soong Yang, Stawarz Lukasz, Sugawara Yasuharu, Sugita Satoshi, Szymkowiak Andrew, Tajima Hiroyasu, Takahashi Hiromitsu, Takahashi Tadayuki, Takeda Shinichiro, Takei Yoh, Tamagawa Toru, Tamura Takayuki, Tanaka Takaaki, Tanaka Yasuo, Tanaka Yasuyuki T., Tashiro Makoto S., Tawara Yuzuru, Terada Yukikatsu, Terashima Yuichi, Tombesi Francesco, Tomida Hiroshi, Tsuboi Yohko, Tsujimoto Masahiro, Tsunemi Hiroshi, Tsuru Takeshi Go, Uchida Hiroyuki, Uchiyama Hideki, Uchiyama Yasunobu, Ueda Shutaro, Ueda Yoshihiro, Uno Shinichiro, Urry C. Megan, Ursino Eugenio, Watanabe Shin, Werner Norbert, Wilkins Dan R., Williams Brian J., Yamada Shinya, Yamaguchi Hiroya, Yamaoka Kazutaka, Yamasaki Noriko Y., Yamauchi Makoto, Yamauchi Shigeo, Yaqoob Tahir, Yatsu Yoichi, Yonetoku Daisuke, Zhuravleva Irina, Zoghbi Abderahmen, Terasawa Toshio, Sekido Mamoru, Takefuji Kazuhiro, Kawai Eiji, Misawa Hiroaki, Tsuchiya Fuminori, Yamazaki Ryo, Kobayashi Eiji, Kisaka Shota, Aoki Takahiro

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    掲載種別:研究論文(学術雑誌)  

    DOI: 10.1093/pasj/psx083

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    PubMed

  88. Hitomi observations of the LMC SNR N 132 D: Highly redshifted X-ray emission from iron ejecta 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Norukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sato, T; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    We present Hitomi observations of N 132 D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only 3.7 ks, the Soft X-ray Spectrometer (SXS) easily detects the line complexes of highly ionized S K and Fe K with 16-17 counts in each. The Fe feature is measured for the first time at high spectral resolution. Based on the plausible assumption that the Fe K emission is dominated by He-like ions, we find that the material responsible for this Fe emission is highly redshifted at ∼ 800 km s−1 compared to the local LMC interstellar medium (ISM), with a 90% credible interval of 50-1500 km s−1 if a weakly informative prior is placed on possible line broadening. This indicates (1) that the Fe emission arises from the supernova ejecta, and (2) that these ejecta are highly asymmetric, since no blueshifted component is found. The S K velocity is consistent with the local LMC ISM, and is likely from swept-up ISM material. These results are consistent with spatial mapping that shows the He-like Fe concentrated in the interior of the remnant and the S tracing the outer shell. The results also show that even with a very small number of counts, direct velocity measurements from Doppler-shifted lines detected in extended objects like supernova remnants are now possible. Thanks to the very low SXS background of ∼ 1 event per spectral resolution element per 100 ks, such results are obtainable during short pointed or slew observations with similar instruments. This highlights the power of high-spectral-resolution imaging observations, and demonstrates the new window that has been opened with Hitomi and will be greatly widened with future missions such as the X-ray Astronomy Recovery Mission (XARM) and Athena.

    DOI: 10.1093/pasj/psx151

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  89. Hitomi observation of radio galaxy NGC 1275: The first X-ray microcalorimeter spectroscopy of Fe-Kα line emission from an active galactic nucleus 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, OO; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Norukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A; Kawamuro, T

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    The origin of the narrow Fe-Kα fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the broad line region, a molecular torus, or interstellar/intracluster media. In 2016 February-March, we performed the first X-ray microcalorimeter spectroscopy with the Soft X-ray Spectrometer (SXS) on board the Hitomi satellite of the Fanaroff-Riley type I radio galaxy NGC 1275 at the center of the Perseus cluster of galaxies. With the high-energy resolution of ∼5 eV at 6 keV achieved by Hitomi/SXS, we detected the Fe-Kα line with ∼5.4 σ significance. The velocity width is constrained to be 500-1600 km s−1 (FWHM for Gaussian models) at 90% confidence. The SXS also constrains the continuum level from the NGC 1275 nucleus up to ∼20 keV, giving an equivalent width of ∼20 eV for the 6.4 keV line. Because the velocity width is narrower than that of the broad Hα line of ∼2750 km s−1, we can exclude a large contribution to the line flux from the accretion disk and the broad line region. Furthermore, we performed pixel map analyses on the Hitomi/SXS data and image analyses on the Chandra archival data, and revealed that the Fe-Kα line comes from a region within ∼1.6 kpc of the NGC 1275 core, where an active galactic nucleus emission dominates, rather than that from intracluster media. Therefore, we suggest that the source of the Fe-Kα line from NGC 1275 is likely a low-covering-fraction molecular torus or a rotating molecular disk which probably extends from a parsec to hundreds of parsecs scale in the active galactic nucleus system.

    DOI: 10.1093/pasj/psx147

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  90. Glimpse of the highly obscured HMXB IGR J16318-4848 with Hitomi 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, OO; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Norukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A; Nakaniwa, N

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    We report on a Hitomi observation of IGRJ16318-4848, a high-mass X-ray binary system with an extremely strong absorption of NH ∼ 1024cm 2. Previous X-ray studies revealed that its spectrum is dominated by strong fluorescence lines of Fe as well as continuum emission lines. For physical and geometrical insight into the nature of the reprocessing material, we utilized the high spectroscopic resolving power of the X-ray microcalorimeter (the soft X-ray spectrometer: SXS) and the wide-band sensitivity by the soft and hard X-ray imagers (SXI and HXI) aboard Hitomi. Even though the photon counts are limited due to unintended off-axis pointing, the SXS spectrum resolves Fe Kα1 and Kα2 lines and puts strong constraints on the line centroid and line width. The line width corresponds to a velocity of 160+-37000 km s-1. This represents the most accurate, and smallest, width measurement of this line made so far from the any X-ray binary, much less than the Doppler broadening and Doppler shift expected from speeds that are characteristic of similar systems. Combined with the K-shell edge energy measured by the SXI and HXI spectra, the ionization state of Fe is estimated to be in the range of Fe I-IV. Considering the estimated ionization parameter and the distance between the X-ray source and the absorber, the density and thickness of the materials are estimated. The extraordinarily strong absorption and the absence of a Compton shoulder component have been confirmed. These characteristics suggest reprocessing materials that are distributed in a narrow solid angle or scattering, primarily by warm free electrons or neutral hydrogen. This measurement was achieved using the SXS detection of 19 photons. It provides strong motivation for follow-up observations of this and other X-ray binaries using the X-ray Astrophysics Recovery Mission and other comparable future instruments.

    DOI: 10.1093/pasj/psx154

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  91. Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hell, N; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, OO; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Norukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A; Raassen, AJJ

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    The Hitomi Soft X-ray Spectrometer spectrum of the Perseus cluster, with ∼5 eV resolution in the 2-9 keV band, offers an unprecedented benchmark of the atomic modeling and database for hot collisional plasmas. It reveals both successes and challenges of the current atomic data and models. The latest versions of AtomDB/APEC (3.0.8), SPEX (3.03.00), and CHIANTI (8.0) all provide reasonable fits to the broad-band spectrum, and are in close agreement on best-fit temperature, emission measure, and abundances of a few elements such as Ni. For the Fe abundance, the APEC and SPEX measurements differ by 16%, which is 17 times higher than the statistical uncertainty. This is mostly attributed to the differences in adopted collisional excitation and dielectronic recombination rates of the strongest emission lines. We further investigate and compare the sensitivity of the derived physical parameters to the astrophysical source modeling and instrumental effects. The Hitomi results show that accurate atomic data and models are as important as the astrophysical modeling and instrumental calibration aspects. Substantial updates of atomic databases and targeted laboratory measurements are needed to get the current data and models ready for the data from the next Hitomi-level mission.

    DOI: 10.1093/pasj/psx156

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  92. Temperature structure in the Perseus cluster core observed with Hitomi 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; de Plaa, J; de Vries, CP; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furukawa, M; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, LY; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Kato, Y; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Norukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; Watanabe, S; Werner, N; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( 2 )   2018年3月

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    The present paper explains the temperature structure of X-ray emitting plasma in the core of the Perseus cluster based on 1.8-20.0 keV data obtained with the Soft X-ray Spectrometer (SXS) on board the Hitomi Observatory. A series of four observations was carried out, with a total effective exposure time of 338 ks that covered a central region of ∼7 in diameter. SXS was operated with an energy resolution of ∼5 eV (full width at half maximum) at 5.9 keV. Not only fine structures of K-shell lines in He-like ions, but also transitions from higher principal quantum numbers were clearly resolved from Si through Fe. That enabled us to perform temperature diagnostics using the line ratios of Si, S, Ar, Ca, and Fe, and to provide the first direct measurement of the excitation temperature and ionization temperature in the Perseus cluster. The observed spectrum is roughly reproduced by a single-temperature thermal plasma model in collisional ionization equilibrium, but detailed line-ratio diagnostics reveal slight deviations from this approximation. In particular, the data exhibit an apparent trend of increasing ionization temperature with the atomic mass, as well as small differences between the ionization and excitation temperatures for Fe, the only element for which both temperatures could be measured. The best-fit two-temperature models suggest a combination of 3 and 5 keV gas, which is consistent with the idea that the observed small deviations from a single-temperature approximation are due to the effects of projecting the known radial temperature gradient in the cluster core along the line of sight. A comparison with the Chandra/ACIS and the XMM-Newton/RGS results, on the other hand, suggests that additional lower-temperature components are present in the intracluster medium (ICM), but not detectable with Hitomi/SXS giving its 1.8-20 keV energy band.

    DOI: 10.1093/pasj/psy004

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  93. An estimation of the white dwarf mass in the Dwarf Nova GK Persei with <i>NuSTAR</i> observations of two states 査読有り

    Wada, Y; Yuasa, T; Nakazawa, K; Makishima, K; Hayashi, T; Ishida, M

    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY   474 巻 ( 2 ) 頁: 1564 - 1571   2018年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Monthly Notices of the Royal Astronomical Society  

    We report on X-ray observations of the Dwarf Nova GK Persei performed by NuSTAR in 2015. GK Persei, behaving also as an Intermediate Polar, exhibited a Dwarf Nova outburst in 2015 March-April. The object was observed with NuSTAR during the outburst state, and again in a quiescent state wherein the 15-50 keV flux was 33 times lower. Using a multitemperature plasma emission and reflection model, the highest plasma temperature in the accretion column was measured as 19.7-1.0+1.3 keV in outburst and 36.2-3.2+3.5 keV in quiescence. The significant change of the maximum temperature is considered to reflect an accretion-induced decrease of the inner-disc radius Rin, where accreting gas is captured by the magnetosphere. Assuming this radius scales as Rin ∝ M˙ -2/7, where M˙ is themass accretion rate, we obtain Rin = 1.9-0.2+0.4 RWD and Rin = 7.4-1.2+2.1 RWD in outburst and quiescence, respectively, where RWD is the white-dwarf (WD) radius of this system. Utilizing the measured temperatures and fluxes, as well as the standard mass-radius relation ofWDs, we estimate the WD mass as MWD = 0.87 ± 0.08M⊙ including typical systematic uncertainties by 7 per cent. The surface magnetic field is also measured as B ~ 5 × 105 G. These results exemplify a new X-ray method of estimating MWD and B of WDs by using large changes in M.

    DOI: 10.1093/mnras/stx2880

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  94. The hitomi X-Ray observatory 査読有り

    Richard L. Kelley, Kazuhiro Nakazawa

    Journal of Astronomical Telescopes, Instruments, and Systems   4 巻 ( 1 )   2018年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPIE  

    DOI: 10.1117/1.JATIS.4.1.011201

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  95. Multiwavelength study of X-ray luminous clusters in the Hyper Suprime-Cam Subaru Strategic Program S16A field 査読有り

    Miyaoka, K; Okabe, N; Kitaguchi, T; Oguri, M; Fukazawa, Y; Mandelbaum, R; Medezinski, E; Babazaki, Y; Nishizawa, AJ; Hamana, T; Lin, YT; Akamatsu, H; Chiu, IN; Fujita, Y; Ichinohe, Y; Komiyama, Y; Sasaki, T; Takizawa, M; Ueda, S; Umetsu, K; Coupon, J; Hikage, C; Hoshino, A; Leauthaud, A; Matsushita, K; Mitsuishi, I; Miyatake, H; Miyazaki, S; More, S; Nakazawa, K; Ota, N; Sato, K; Spergel, D; Tamura, T; Tanaka, M; Tanaka, MM; Utsumi, Y

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   70 巻 ( Special Issue 1 )   2018年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    We present a joint X-ray, optical, and weak-lensing analysis for X-ray luminous galaxy clusters selected from the MCXC (Meta-Catalog of X-Ray Detected Clusters of Galaxies) cluster catalog in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey field with S16A data. As a pilot study for a series of papers, we measure hydrostatic equilibrium (HE) masses using XMM-Newton data for four clusters in the current coverage area out of a sample of 22 MCXC clusters. We additionally analyze a non-MCXC cluster associated with one MCXC cluster. We show that HE masses for the MCXC clusters are correlated with cluster richness from the CAMIRA catalog, while that for the non-MCXC cluster deviates from the scaling relation. The mass normalization of the relationship between cluster richness and HE mass is compatible with one inferred by matching CAMIRA cluster abundance with a theoretical halo mass function. The mean gas mass fraction based on HE masses for the MCXC clusters is (fgas) = 0.125 ± 0.012 at spherical overdensity Δ = 500, which is ∼80%-90% of the cosmic mean baryon fraction, Ωb/Ωm,measured by cosmicmicrowave background experiments. We find that themean baryon fraction estimated from X-ray and HSC-SSP optical data is comparable to Ωb/Ωm. A weak-lensing shear catalog of background galaxies, combined with photometric redshifts, is currently available only for three clusters in our sample. Hydrostatic equilibrium masses roughly agree with weak-lensing masses, albeit with large uncertainty. This study demonstrates that further multi wave length study for a large sample of clusters using X-ray, HSC-SSP optical, and weak-lensing data will enable us to understand cluster physics and utilize cluster-based cosmology.

    DOI: 10.1093/pasj/psx132

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  96. 2015年-2017年冬季の金沢地域における雷雲ガンマ線データの解析

    松元 崇弘, 馬場 彩, 米徳 大輔, 澤野 達哉, 和田 有希, 古田 禄大, 中澤 知洋, 榎戸 輝揚, 湯浅 孝行, 牧島 一夫, 土屋 晴文, 小高 裕和

    日本物理学会講演概要集   73 巻 ( 0 ) 頁: 134 - 134   2018年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.2.0_134

    CiNii Research

  97. Monitoring of gamma-ray bursts with a fleet of nanosatellites

    Řípa J., Werner N., Pál A., Ohno M., Tarcai N., Torigoe K., Tanaka K., Uchida N., Mészáros L., Galgóczi G., Fukazawa Y., Mizuno T., Takahashi H., Nakazawa K., Várhegyi Z., Enoto T., Odaka H., Ichinohe Y., Frei Z., Kiss L.

    Proceedings of the International Astronautical Congress, IAC   2018- 巻   2018年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of the International Astronautical Congress, IAC  

    We present the results of our feasibility study for a fleet of nano-satellites to perform an all sky monitoring and timing-based localisation of gamma-ray transients. The fleet of nine satellites of the CubeSat standard equipped with scintillator based soft gamma-ray detectors will measure the time difference between the arrival of the signal at the different satellites (the time will be synchronised using GPS) and determine the location of bright gamma-ray bursts in the sky by triangulation. The satellites will downlink the data about the detected transient within minutes, enabling rapid follow-up observations at other wavelengths.

    Scopus

  98. Long-term test of a stacked CdTe mini-HXI setup 査読有り

    Daniel Maier, Benoit Horeau, Philippe Laurent, Olivier Limousin, Diana Renaud, Madoka Kawaharada, Motohide Kokubun, Goro Sato, Tadayuki Takahashi, Shin Watanabe, Kazuhiro Nakazawa, Cesar Boatella Polo

    Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment   912 巻   頁: 199 - 204   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier B.V.  

    This work presents a long-term operation of two stacked CdTe double sided strip detectors that are comparable with the CdTe detectors onboard Hitomi's HXI. The goal of this test is to study the evolution of the spectroscopic performance of the detectors during a one year operation cycle which resembles the in-orbit operation cycle of Hitomi HXI. Crystal defects inside CdTe cause a degradation of the spectroscopic performance (polarization effect) of the crystal which is becoming worse during detector operation. In order to prevent crystal polarization, the detectors are reset (switch-off of the depletion voltage) once a day. Our main investigation was to study if a long-term degradation can occur as a result of incomplete depolarization during the reset. We present the hardware setup and the analytical steps that were used to investigate the detector stability during each day and over the whole testing period. For the anode signals our results show at 60 keV: a daily line drift of (−2.8±0.7) eV/ks while the long-term drift is (−1.5±1.2) eV/day. The degradation of the energy resolution is measured to be (+2.4±0.3) eV/ks FWHM and the loss of efficiency is (−0.29±0.02) %/ks.

    DOI: 10.1016/j.nima.2017.11.035

    Scopus

  99. Concept of X-ray Astronomy Recovery Mission 査読有り

    Tashiro, M; Maejima, H; Toda, K; Kelley, R; Reichenthal, L; Lobell, J; Petre, R; Guainazzi, M; Costantini, E; Edison, M; Fujimoto, R; Grim, M; Hayashida, K; den Herder, JW; Ishisaki, Y; Paltani, S; Matsushita, K; Mori, K; Sneiderman, G; Takei, Y; Terada, Y; Tomida, H; Akamatsu, H; Angelini, L; Arai, Y; Awaki, H; Babyk, I; Bamba, A; Barfknecht, P; Barnstable, K; Bialas, T; Blagojevic, B; Bonafede, J; Brambora, C; Brenneman, L; Brown, G; Brown, K; Burns, L; Canavan, E; Carnahan, T; Chiao, M; Comber, B; Corrales, L; de Vries, C; Dercksen, J; Diaz-Trigo, M; Dillard, T; DiPirro, M; Done, C; Dotani, T; Ebisawa, K; Eckart, M; Enoto, T; Ezoe, Y; Ferrigno, C; Fujita, Y; Fukazawa, Y; Furuzawa, A; Gallo, L; Graham, S; Gu, LY; Hagino, K; Hamaguchi, K; Hatsukade, I; Hawes, D; Hayashi, T; Hegarty, C; Hell, N; Hiraga, J; Hodges-Kluck, E; Holland, M; Hornschemeier, A; Hoshino, A; Ichinohe, Y; Iizuka, R; Ishibashi, K; Ishida, M; Ishikawa, K; Ishimura, K; James, B; Kallman, T; Kara, E; Katsuda, S; Kenyon, S; Kilbourne, C; Kimball, M; Kitaguchi, T; Kitamoto, S; Kobayashi, S; Kohmura, T; Koyama, S; Kubota, A; Leutenegger, M; Lockard, T; Loewenstein, M; Maeda, Y; Marbley, L; Markevitch, M; Martz, C; Matsumoto, H; Matsuzaki, K; McCammon, D; McNamara, B; Miko, J; Miller, E; Miller, J; Minesugi, K; Mitsuishi, I; Mizuno, T; Mori, H; Mukai, K; Murakami, H; Mushotzky, R; Nakajima, H; Nakamura, H; Nakashima, S; Nakazawa, K; Natsukari, C; Nigo, K; Nishioka, Y; Nobukawa, K; Nobukawa, M; Noda, H; Odaka, H; Ogawa, M; Ohashi, T; Ohno, M; Ohta, M; Okajima, T; Okamoto, A; Onizuka, M; Ota, N; Ozaki, M; Plucinsky, P; Porter, FS; Pottschmidt, K; Sato, K; Sato, R; Sawada, M; Seta, H; Shelton, K; Shibano, Y; Shida, M; Shidatsu, M; Shirron, P; Simionescu, A; Smith, R; Someya, K; Soong, Y; Sugawara, Y; Szymkowiak, A; Takahashi, H; Tamagawa, T; Tamura, T; Tanaka, T; Terashima, Y; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, T; Uchida, H; Uchiyama, H; Ueda, Y; Uno, S; Walsh, T; Watanabe, S; Williams, B; Wolfs, R; Wright, M; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, N; Yamauchi, S; Yamauchi, M; Yanagase, K; Yaqoob, T; Yasuda, S; Yoshioka, N; Zabala, J; Zhuravleva, I

    SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY   10699 巻   2018年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    The ASTRO-H mission was designed and developed through an international collaboration of JAXA, NASA, ESA, and the CSA. It was successfully launched on February 17, 2016, and then named Hitomi. During the in-orbit verification phase, the on-board observational instruments functioned as expected. The intricate coolant and refrigeration systems for soft X-ray spectrometer (SXS, a quantum micro-calorimeter) and soft X-ray imager (SXI, an X-ray CCD) also functioned as expected. However, on March 26, 2016, operations were prematurely terminated by a series of abnormal events and mishaps triggered by the attitude control system. These errors led to a fatal event: the loss of the solar panels on the Hitomi mission. The X-ray Astronomy Recovery Mission (or, XARM) is proposed to regain the key scientific advances anticipated by the international collaboration behind Hitomi. XARM will recover this science in the shortest time possible by focusing on one of the main science goals of Hitomi,"Resolving astrophysical problems by precise high-resolution X-ray spectroscopy".1 This decision was reached after evaluating the performance of the instruments aboard Hitomi and the mission's initial scientific results, and considering the landscape of planned international X-ray astrophysics missions in 2020's and 2030's. Hitomi opened the door to high-resolution spectroscopy in the X-ray universe. It revealed a number of discrepancies between new observational results and prior theoretical predictions. Yet, the resolution pioneered by Hitomi is also the key to answering these and other fundamental questions. The high spectral resolution realized by XARM will not offer mere refinements; rather, it will enable qualitative leaps in astrophysics and plasma physics. XARM has therefore been given a broad scientific charge: "Revealing material circulation and energy transfer in cosmic plasmas and elucidating evolution of cosmic structures and objects". To fulfill this charge, four categories of science objectives that were defined for Hitomi will also be pursued by XARM; these include (1) Structure formation of the Universe and evolution of clusters of galaxies; (2) Circulation history of baryonic matters in the Universe; (3) Transport and circulation of energy in the Universe; (4) New science with unprecedented high resolution X-ray spectroscopy. In order to achieve these scientific objectives, XARM will carry a 6 × 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly, and an aligned X-ray CCD camera covering the same energy band and a wider field of view. This paper introduces the science objectives, mission concept, and observing plan of XARM.

    DOI: 10.1117/12.2309455

    Web of Science

    Scopus

  100. CAMELOT: design and performance verification of the detector concept and localization capability

    Ohno, M; Werner, N; Pál, A; Rípa, J; Galgóczi, G; Tarcai, N; Várhegyi, Z; Fukazawa, Y; Mizuno, T; Takahashi, H; Tanaka, K; Uchida, N; Torigoe, K; Nakazawa, K; Enoto, T; Odaka, H; Ichinohe, Y; Frei, Z; Kiss, L

    SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY   10699 巻   2018年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    A fleet of nanosatellites using precise timing synchronization provided by the Global Positioning System is a new concept for monitoring the gamma-ray sky that can achieve both all-sky coverage and good localization accuracy. We are proposing this new concept for the mission CubeSats Applied for MEasuring and LOcalising Transients (CAMELOT). The differences in photon arrival times at each satellite are to be used for source localization. Detectors with good photon statistics and the development of a localization algorithm capable of handling a large number of satellites are both essential for this mission. Large, thin CsI scintillator plates are the current candidates for the detectors because of their high light yields. It is challenging to maximize the light-collection efficiency and to understand the position dependence of such thin plates. We have found a multi-channel readout that uses the coincidence technique to be very effective in increasing the light output while keeping a similar noise level to that of a single channel readout. Based on such a detector design, we have developed a localization algorithm for this mission and have found that we can achieve a localization accuracy better than 20 arc minutes and a rate of about 10 short gamma-ray bursts per year.

    DOI: 10.1117/12.2313228

    Web of Science

    Scopus

  101. CAMELOT: Cubesats Applied for MEasuring and LOcalising Transients - Mission Overview

    Werner, N; Rípa, J; Pál, A; Ohno, M; Tarcai, N; Torigoe, K; Tanaka, K; Uchida, N; Mészáros, L; Galgóczi, G; Fukazawa, Y; Mizuno, T; Takahashi, H; Nakazawa, K; Várhegyi, Z; Enoto, T; Odaka, H; Ichinohe, Y; Frei, Z; Kiss, L

    SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY   10699 巻   2018年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    We propose a fleet of nanosatellites to perform an all-sky monitoring and timing based localisation of gamma-ray transients. The fleet of at least nine 3U cubesats shall be equipped with large and thin CsI(Tl) scintillator based soft gamma-ray detectors read out by multi-pixel photon counters. For bright short gamma-ray bursts (GRBs), by cross-correlating their light curves, the fleet shall be able to determine the time difference of the arriving GRB signal between the satellites and thus determine the source position with an accuracy of ∼ 100. This requirement demands precise time synchronization and accurate time stamping of the detected gamma-ray photons, which will be achieved by using on-board GPS receivers. Rapid follow up observations at other wavelengths require the capability for fast, nearly simultaneous downlink of data using a global inter-satellite communication network. In terms of all-sky coverage, the proposed fleet will outperform all GRB monitoring missions.

    DOI: 10.1117/12.2313764

    Web of Science

    Scopus

  102. CAMELOT - Concept study and early results for onboard data processing and GPS-based timestamping

    András Pál, László Mészáros, Norbert Tarcai, Norbert Werner, Jakub Řípa, Masanori Ohno, Kento Torigoe, Koji Tanaka, Nagomi Uchida, Gabór Galgóczi, Yasushi Fukazawa, Tsunefumi Mizuno, Hiromitsu Takahashi, Kazuhiro Nakazawa, Zsolt Várhegyi, Teruaki Enoto, Hirokazu Odaka, Yuto Ichinohe, Zsolt Frei, László Kiss

    arXiv     2018年

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    記述言語:英語  

  103. The FORCE mission : Science aim and instrument parameter for broadband X-ray imaging spectroscopy with good angular resolution

    Nakazawa, K; Mori, K; Tsuru, TG; Ueda, Y; Awaki, H; Fukazawa, Y; Ishida, M; Matsumoto, H; Murakami, H; Okajima, T; Takahashi, T; Tsunemi, H; Zhang, WW

    SPACE TELESCOPES AND INSTRUMENTATION 2018: ULTRAVIOLET TO GAMMA RAY   10699 巻   2018年

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    掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Proceedings of SPIE - The International Society for Optical Engineering  

    FORCE is a 1.2 tonnes small mission dedicated for wide-band fine-imaging<br />
    x-ray observation. It covers from 1 to 80 keV with a good angular resolution of<br />
    $15&quot;$ half-power-diameter. It is proposed to be launched around mid-2020s and<br />
    designed to reach a limiting sensitivity as good as $F_X (10-40~{\rm keV}) = 3<br />
    \times 10^{-15}$~erg cm$^{-2}$ s$^{-1}$ keV$^{-1}$ within 1~Ms. This number is<br />
    one order of magnitude better than current best one. With its high-sensitivity<br />
    wide-band coverage, FORCE will probe the new science field of &quot;missing BHs&quot;,<br />
    searching for families of black holes of which populations and evolutions are<br />
    not well known. Other point-source and diffuse-source sciences are also<br />
    considered. FORCE will also provide the &quot;hard x-ray coverage&quot; to forthcoming<br />
    large soft x-ray observatories.

    DOI: 10.1117/12.2309344

    Web of Science

    Scopus

    arXiv

  104. 雷雲ガンマ線の観測プロジェクトと雷での光核反応の検出

    榎戸 輝揚, 和田 有希, 古田 禄大, 中澤 知洋, 湯浅 孝行, 奥田 和史, 牧島 一夫, 佐藤 光輝, 佐藤 陽祐, 中野 俊男, 楳本 大悟, 土屋 晴文

    日本物理学会講演概要集   73.1 巻 ( 0 ) 頁: 176 - 176   2018年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.1.0_176

    CiNii Research

  105. 衛星軌道上放射化バックグラウンドシミュレータの開発と「ひとみ」衛星搭載硬X線撮像検出器のデータの再現性

    小高 裕和, 萩野 浩一, 水野 恒史, 大野 雅功, 斉藤 新也, 中澤 知洋

    日本物理学会講演概要集   73.2 巻 ( 0 ) 頁: 163 - 163   2018年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.2.0_163

    CiNii Research

  106. 落雷による光核反応の発見:地上観測による中性子と陽電子の検出

    和田 有希, 古田 禄大, 榎戸 輝揚, 中澤 知洋, 湯浅 孝行, 奥田 和史, 牧島 一夫, 佐藤 光輝, 佐藤 陽祐, 中野 俊男, 鈴木 寛大, 楳本 大悟, 土屋 晴文

    日本物理学会講演概要集   73.1 巻 ( 0 ) 頁: 422 - 422   2018年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.1.0_422

    CiNii Research

  107. 大型 CsI 結晶を用いた冬季雷雲由来ガンマ線検出器の量産とそれを用いたマッピング観測

    松元 崇弘, 和田 有希, 古田 禄大, 清野 愛海, 中澤 知洋, 榎戸 輝揚, 湯浅 孝行, 牧島 一夫, 中野 俊男, 土屋 晴文

    日本物理学会講演概要集   73.1 巻 ( 0 ) 頁: 414 - 414   2018年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.1.0_414

    CiNii Research

  108. Multi-point Measurement Campaigns of Gamma Rays from Thunderclouds and Lightning in Japan 国際共著

    中澤 知洋, 土屋 晴文

    Proceedings of XVI International Conference on Atmospheric Electricity   - 巻   頁: 1 - 13   2018年

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  109. Suzaku and Chandra observations of the galaxy cluster RXC J1053.7+5453 with a radio relic 査読有り

    Itahana Madoka, Takizawa Motokazu, Akamatsu Hiroki, van Weeren Reinout J, Kawahara Hajime, Fukazawa Yasushi, Kaastra Jelle S, Nakazawa Kazuhiro, Ohashi Takaya, Ota Naomi, Rottgering Huub J. A, Vink Jacco, Zandanel Fabio

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   69 巻 ( 6 )   2017年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1093/pasj/psx095

    Web of Science

  110. Photonuclear reactions triggered by lightning discharge 査読有り

    Enoto, T; Wada, Y; Furuta, Y; Nakazawa, K; Yuasa, T; Okuda, K; Makishima, K; Sato, M; Sato, Y; Nakano, T; Umemoto, D; Tsuchiya, H

    NATURE   551 巻 ( 7681 ) 頁: 481 - +   2017年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nature  

    Lightning and thunderclouds are natural particle accelerators. Avalanches of relativistic runaway electrons, which develop in electric fields within thunderclouds, emit bremsstrahlung Î 3-rays. These Î 3-rays have been detected by ground-based observatories, by airborne detectors and as terrestrial Î 3-ray flashes from space. The energy of the Î 3-rays is sufficiently high that they can trigger atmospheric photonuclear reactions that produce neutrons and eventually positrons via β + decay of the unstable radioactive isotopes, most notably 13 N, which is generated via 14 N + Î 3 â †' 13 N + n, where Î 3 denotes a photon and n a neutron. However, this reaction has hitherto not been observed conclusively, despite increasing observational evidence of neutrons and positrons that are presumably derived from such reactions. Here we report ground-based observations of neutron and positron signals after lightning. During a thunderstorm on 6 February 2017 in Japan, a Î 3-ray flash with a duration of less than one millisecond was detected at our monitoring sites 0.5-1.7 kilometres away from the lightning. The subsequent Î 3-ray afterglow subsided quickly, with an exponential decay constant of 40-60 milliseconds, and was followed by prolonged line emission at about 0.511 megaelectronvolts, which lasted for a minute. The observed decay timescale and spectral cutoff at about 10 megaelectronvolts of the Î 3-ray afterglow are well explained by de-excitation Î 3-rays from nuclei excited by neutron capture. The centre energy of the prolonged line emission corresponds to electron-positron annihilation, providing conclusive evidence of positrons being produced after the lightning.

    DOI: 10.1038/nature24630

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    PubMed

  111. Solar abundance ratios of the iron-peak elements in the Perseus cluster 査読有り

    Aharonian, F; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, R; Brenneman, LW; Brown, GV; Bulbul, E; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, PS; Costantini, E; De Plaa, J; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, L; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, IM; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, JS; Hornschemeier, A; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, Y; Ishida, M; Ishikawa, K; Ishisaki, Y; Iwai, M; Kaastra, J; Kallman, T; Kamae, T; Kataoka, J; Katsuda, S; Kawai, N; Kelley, RL; Kilbourne, CA; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, K; Koyama, S; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lee, SH; Leutenegger, MA; Limousine, O; Loewenstein, M; Long, KS; Lumb, D; Madejski, G; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Mukai, K; Murakami, H; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakashima, S; Nakazawa, K; Nobukawa, KK; Nobukawa, M; Noda, H; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Petre, R; Pinto, C; Porter, FS; Pottschmidt, K; Reynolds, CS; Safi-Harb, S; Saito, S; Sakai, K; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, A; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, YT; Tashiro, MS; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, TG; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Uno, S; Urry, CM; Ursino, E; de Vries, CP; Watanabe, S; Werner, N; Wik, DR; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Zhuravleva, I; Zoghbi, A

    NATURE   551 巻 ( 7681 ) 頁: 478 - +   2017年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Nature  

    The metal abundance of the hot plasma that permeates galaxy clusters represents the accumulation of heavy elements produced by billions of supernovae. Therefore, X-ray spectroscopy of the intracluster medium provides an opportunity to investigate the nature of supernova explosions integrated over cosmic time. In particular, the abundance of the iron-peak elements (chromium, manganese, iron and nickel) is key to understanding how the progenitors of typical type Ia supernovae evolve and explode. Recent X-ray studies of the intracluster medium found that the abundance ratios of these elements differ substantially from those seen in the Sun, suggesting differences between the nature of type Ia supernovae in the clusters and in the Milky Way. However, because the K-shell transition lines of chromium and manganese are weak and those of iron and nickel are very close in photon energy, high-resolution spectroscopy is required for an accurate determination of the abundances of these elements. Here we report observations of the Perseus cluster, with statistically significant detections of the resonance emission from chromium, manganese and nickel. Our measurements, combined with the latest atomic models, reveal that these elements have near-solar abundance ratios with respect to iron, in contrast to previous claims. Comparison between our results and modern nucleosynthesis calculations disfavours the hypothesis that type Ia supernova progenitors are exclusively white dwarfs with masses well below the Chandrasekhar limit (about 1.4 times the mass of the Sun). The observed abundance pattern of the iron-peak elements can be explained by taking into account a combination of near- A nd sub-Chandrasekhar-mass type Ia supernova systems, adding to the mounting evidence that both progenitor types make a substantial contribution to cosmic chemical enrichment.

    DOI: 10.1038/nature24301

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    PubMed

  112. Suzaku Wide-band All-sky Monitor (WAM) observations of GRBs and SGRs 査読有り

    Yamaoka, K; Ohno, M; Tashiro, MS; Hurley, K; Krimm, HA; Lien, AY; Ohmori, N; Sugita, S; Urata, Y; Yasuda, T; Enomoto, J; Fujinuma, T; Fukazawa, Y; Hanabata, Y; Iwakiri, W; Kawano, T; Kinoshita, R; Kokubun, M; Makishima, K; Matsuoka, S; Nagayoshi, T; Nakagawa, Y; Nakaya, S; Nakazawa, K; Nishioka, Y; Sakamoto, T; Takahashi, T; Takeda, S; Terada, Y; Yabe, S; Yamauchi, M; Yoshida, H

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   69 巻 ( 3 )   2017年6月

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    記述言語:英語   出版者・発行元:Publications of the Astronomical Society of Japan  

    We will review results for gamma-ray bursts (GRBs) and soft gamma repeaters (SGRs), obtained from the Suzaku Wide-band All-sky Monitor (WAM) which operated for about 10 years from 2005 to 2015. The WAM is a BGO (bismuth germanate: Bi 4 Ge 3 O 12) lateral shield for the Hard X-ray Detector (HXD), used mainly for rejecting its detector background, but it also works as an all-sky monitor for soft gamma-ray transients in the 50-5000 keV range thanks to its large effective area (∼600 cm 2 at 1 MeV for one detector) and wide field of view (about half of the entire sky). The WAM actually detected more than 1400 GRBs and 300 bursts from SGRs, and this detection number is comparable to that of other GRB-specific instruments. Based on the 10 years of operation, we describe timing and spectral performance for short GRBs, weak GRBs with high redshifts, and time-resolved pulses with good statistics.

    DOI: 10.1093/pasj/psx026

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  113. A hard-to-soft state transition of Aquila X-1 observed with Suzaku 査読有り

    Ono, K; Makishima, K; Sakurai, S; Zhang, ZL; Yamaoka, K; Nakazawa, K

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   69 巻 ( 2 )   2017年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    The recurrent soft X-ray transient Aquila X-1 was observed with Suzaku for a gross duration of 79.9 ks, on 2011 October 21 when the object was in a rising phase of an outburst. During the observation, the source exhibited a clear spectral transition from the hard state to the soft state, on a time scale of ∼30 ks. Across the transition, the 0.8-10 keV X-Ray Imaging Spectrometer count rate increased by a factor ∼3, that of Hard X-ray Detector PIN (HXD-PIN) in 15-60 keV decreased by a similar factor, and the unabsorbed 0.1-100 keV luminosity increased from 3.5 × 1037 erg s-1 to 5.1 × 1037 erg s-1. The broadband spectral shape changed continuously, from a power-law-like one with a high-energy cut-off to a more convex one. Throughout the transition, the 0.8-60 keV spectra were successfully described with a model consisting of a multi-color blackbody and a Comptonized blackbody, which are considered to arise from a standard accretion disk and a closer vicinity of the neutron star, respectively. All the model parameters were confirmed to change continuously, from those typical in the hard state to those typical of the soft state. More specifically, the inner disk radius decreased from 31 km to 18 km, the effects of Comptonization on the blackbody photons weakened, and the electron temperature of Comptonization decreased from 10 keV to 3 keV. The derived parameters imply that the Comptonizing corona shrinks towards the final soft state, and/or the radial infall velocity of the corona decreases. These results reinforce the view that the soft and hard states of Aql X-1 (and of similar objects) are described by the same "disk plus Comptonized blackbody" model, but with considerably different parameters.

    DOI: 10.1093/pasj/psw126

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  114. Suzaku observations of the merging galaxy cluster Abell 2255: The northeast radio relic 査読有り

    H. Akamatsu, M. Mizuno, N. Ota, Y-Y. Zhang, R. J. van Weeren, H. Kawahara, Y. Fukazawa, J. S. Kaastra, M. Kawaharada, K. Nakazawa, T. Ohashi, H. J. A. Rottgering, M. Takizawa, J. Vink, F. Zandanel

    ASTRONOMY & ASTROPHYSICS   600 巻   頁: A100   2017年4月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:EDP SCIENCES S A  

    We present the results of deep 140 ks Suzaku X-ray observations of the north-east (NE) radio relic of the merging galaxy cluster Abell 2255. The temperature structure of Abell 2255 is measured out to 0.9 times the virial radius (1.9 Mpc) in the NE direction for the first time. The Suzaku temperature map of the central region suggests a complex temperature distribution, which agrees with previous work. Additionally, on a larger-scale, we confirm that the temperature drops from 6 keV around the cluster center to 3 keV at the outskirts, with two discontinuities at r similar to 5' (450 kpc) and similar to 12' (1100 kpc) from the cluster center. Their locations coincide with surface brightness discontinuities marginally detected in the XMM-Newton image, which indicates the presence of shock structures. From the temperature drop, we estimate the Mach numbers to be M-inner similar to 1.2 and, M-outer similar to 1:4. The first structure is most likely related to the large cluster core region (similar to 350-430 kpc), and its Mach number is consistent with the XMM-Newton observation (M similar to 1.24: Sakelliou & Ponman 2006, MNRAS, 367, 1409). Our detection of the second temperature jump, based on the Suzaku key project observation, shows the presence of a shock structure across the NE radio relic. This indicates a connection between the shock structure and the relativistic electrons that generate radio emission. Across the NE radio relic, however, we find a significantly lower temperature ratio (T-1/T-2 similar to 1.44 +/- 0.16 corresponds to M-X (ray) similar to 1.4) than the value expected from radio wavelengths, based on the standard diffusive shock acceleration mechanism (T-1/T-2 &gt; 3.2 or M-Radio &gt; 2.8). This may suggest that under some conditions, in particular the NE relic of A2255 case, the simple diffusive shock acceleration mechanism is unlikely to be valid, and therefore, more a sophisticated mechanism is required.

    DOI: 10.1051/0004-6361/201628400

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  115. <i>Hitomi</i> Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster 査読有り

    Aharonian, FA; Akamatsu, H; Akimoto, F; Allen, SW; Angelini, L; Arnaud, KA; Audard, M; Awaki, H; Axelsson, M; Bamba, A; Bautz, MW; Blandford, RD; Bulbul, E; Brenneman, LW; Brown, GV; Cackett, EM; Chernyakova, M; Chiao, MP; Coppi, P; Costantini, E; de Plaa, J; den Herder, JW; Done, C; Dotani, T; Ebisawa, K; Eckart, ME; Enoto, T; Ezoe, Y; Fabian, AC; Ferrigno, C; Foster, AR; Fujimoto, R; Fukazawa, Y; Furuzawa, A; Galeazzi, M; Gallo, LC; Gandhi, P; Giustini, M; Goldwurm, A; Gu, L; Guainazzi, M; Haba, Y; Hagino, K; Hamaguchi, K; Harrus, I; Hatsukade, I; Hayashi, K; Hayashi, T; Hayashida, K; Hiraga, J; Hornschemeier, AE; Hoshino, A; Hughes, JP; Ichinohe, Y; Iizuka, R; Inoue, H; Inoue, S; Inoue, Y; Ishibashi, K; Ishida, M; Ishikawa, K; Ishisaki, Y; Itoh, M; Iwai, M; Iyomoto, N; Kaastra, JS; Kallman, T; Kamae, T; Kara, E; Kataoka, J; Katsuda, S; Katsuta, J; Kawaharada, M; Kawai, N; Kelley, RL; Khangulyan, D; Kilbourne, CA; King, AL; Kitaguchi, T; Kitamoto, S; Kitayama, T; Kohmura, T; Kokubun, M; Koyama, S; Koyama, K; Kretschmar, P; Krimm, HA; Kubota, A; Kunieda, H; Laurent, P; Lebrun, F; Lee, SH; Leutenegger, MA; Limousin, O; Loewenstein, M; Long, KS; Lumb, DH; Madejski, GM; Maeda, Y; Maier, D; Makishima, K; Markevitch, M; Matsumoto, H; Matsushita, K; McCammon, D; McNamara, BR; Mehdipour, M; Miller, ED; Miller, JM; Mineshige, S; Mitsuda, K; Mitsuishi, I; Miyazawa, T; Mizuno, T; Mori, H; Mori, K; Moseley, H; Mukai, K; Murakami, H; Murakami, T; Mushotzky, RF; Nakagawa, T; Nakajima, H; Nakamori, T; Nakano, T; Nakashima, S; Nakazawa, K; Nobukawa, K; Nobukawa, M; Noda, H; Nomachi, M; O'Dell, SL; Odaka, H; Ohashi, T; Ohno, M; Okajima, T; Ota, N; Ozaki, M; Paerels, F; Paltani, S; Parmar, A; Petre, R; Pinto, C; Pohl, M; Porter, FS; Pottschmidt, K; Ramsey, BD; Reynolds, CS; Russell, HR; Safi-Harb, S; Saito, S; Sakai, K; Sameshima, H; Sasaki, T; Sato, G; Sato, K; Sato, R; Sawada, M; Schartel, N; Serlemitsos, PJ; Seta, H; Shidatsu, M; Simionescu, A; Smith, RK; Soong, Y; Stawarz, L; Sugawara, Y; Sugita, S; Szymkowiak, AE; Tajima, H; Takahashi, H; Takahashi, T; Takeda, S; Takei, Y; Tamagawa, T; Tamura, K; Tamura, T; Tanaka, T; Tanaka, Y; Tanaka, Y; Tashiro, M; Tawara, Y; Terada, Y; Terashima, Y; Tombesi, F; Tomida, H; Tsuboi, Y; Tsujimoto, M; Tsunemi, H; Tsuru, T; Uchida, H; Uchiyama, H; Uchiyama, Y; Ueda, S; Ueda, Y; Ueno, S; Uno, S; Urry, CM; Ursino, E; de Vries, CP; Watanabe, S; Werner, N; Wik, DR; Wilkins, DR; Williams, BJ; Yamada, S; Yamaguchi, H; Yamaoka, K; Yamasaki, NY; Yamauchi, M; Yamauchi, S; Yaqoob, T; Yatsu, Y; Yonetoku, D; Yoshida, A; Zhuravleva, I; Zoghbi, A

    ASTROPHYSICAL JOURNAL LETTERS   837 巻 ( 1 ) 頁: 668 - 672   2017年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Astrophysical Journal Letters  

    High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E ≈ 3.5 keV emission line reported in several low-resolution studies of various massive systems, such as galaxies and clusters, including the Perseus cluster. We have analyzed the Hitomi first-light observation of the Perseus cluster. The emission line expected for Perseus based on the XMM-Newton signal from the large cluster sample under the dark matter decay scenario is too faint to be detectable in the Hitomi data. However, the previously reported 3.5 keV flux from Perseus was anomalously high compared to the sample-based prediction. We find no unidentified line at the reported high flux level. Taking into account the XMM measurement uncertainties for this region, the inconsistency with Hitomi is at a 99% significance for a broad dark matter line and at 99.7% for a narrow line from the gas. We do not find anomalously high fluxes of the nearby faint K line or the Ar satellite line that were proposed as explanations for the earlier 3.5 keV detections. We do find a hint of a broad excess near the energies of high-n transitions of S xvi (E ≃ 3.44 keV rest-frame) - a possible signature of charge exchange in the molecular nebula and another proposed explanation for the unidentified line. While its energy is consistent with XMM pn detections, it is unlikely to explain the MOS signal. A confirmation of this interesting feature has to wait for a more sensitive observation with a future calorimeter experiment.

    DOI: 10.3847/2041-8213/aa61fa

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  116. Suzaku and Chandra observations of CIZA J1700.8-3144, a cluster of galaxies in the Zone of Avoidance 査読有り

    Mori, H; Maeda, Y; Ueda, Y; Nakazawa, K; Tawara, Y

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   69 巻 ( 1 )   2017年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Publications of the Astronomical Society of Japan  

    We present the Chandra and Suzaku observations of 1RXS J170047.8-314442, located towards the Galactic bulge, to reveal a wide-band (0.3-10keV) X-ray morphology and spectrum of this source. With the Chandra observation, no point source was found at the position of 1RXS J170047.8-314442. Instead, we revealed the presence of diffuse X-ray emission, via the wide-band X-ray image obtained from the Suzaku XIS. Although the X-rayemission had a nearly circularshape with a spatial extent of ∼3.5, the surface brightness profile was not axisymmetric; a bright spot-like emission was found at ∼ 1' away in the northwestern direction from the center. The radial profile of the surface brightness, except for this spot-like emission, was reproduced with a single β-model; β and the core radius were found to be 1.02 and 1.51, respectively. The X-ray spectrum of the diffuse emission showed an emission line at ∼6keV, indicating an origin of a thermal plasma. The spectrum was well explained with an absorbed, optically-thin thermal plasma model with a temperature of 6.2 keVand a redshift parameter of z= 0.14 ±0.01. Hence, the X-ray emission was considered to arise from the hot gas associated with a cluster of galaxies. Our spectroscopic result confirmed the optical identification of 1RXS J170047.8-314442 by Kocevski et al. (2007, ApJ, 662, 224): CIZAJ1700.8-3144, a member of the cluster catalogue in the Zone of Avoidance. The estimated bolometric X-ray luminosity of 5.9 × 1044 erg s-1 was among the lowest with this temperature, suggesting that this cluster is far from relaxed.

    DOI: 10.1093/pasj/psw106

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  117. Suzaku observations of spectral variations of the ultra-luminous X-ray source Holmberg IX X-1 査読有り

    Shogo B. Kobayashi, Kazuhiro Nakazawa, Kazuo Makishima

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   69 巻 ( 1 )   2017年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OXFORD UNIV PRESS  

    Observations of the ultra-luminous X-ray source (ULX) Holmberg IX X-1 were carried out with Suzaku twice, once on 2012 April 13 and then on 2012 October 24, with exposures of 180 ks and 217 ks, respectively. The source showed a hard power-law shaped spectrum with a mild cutoff at similar to 8 keV, which is typical of ULXs when they are relatively dim. On both occasions, the 0.6-11 keV spectrum was explained successfully in terms of a cool (similar to 0.2 keV) multi-color disk blackbody emission model and thermal Comptonization emission produced by an electron cloud with a relatively low temperature and high optical depth, assuming that a large fraction of the disk-blackbody photons are Comptonized whereas the rest are observed directly. The 0.5-10 keV luminosity was 1.2 x 10(40) erg s(-1) in April, and similar to 14% higher in October. This brightening was accompanied by spectral softening in &gt;= 2 keV, with little change in the &lt;= 2 keV spectral shape. This behavior can be understood if the accretion disk remains unchanged while the electron cloud covers a variable fraction of the disk. The absorbing column density was consistent with the galactic line-of sight value, and did not vary by more than 1.6 x 10(21) cm(-2). Together with the featureless spectra, these properties may not be reconciled easily with the supercritical accretion scenario of this source.

    DOI: 10.1093/pasj/psw108

    Web of Science

  118. NuSTAR Observations of the Dwarf Nova GK Persei in 2015: Comparison between Outburst and Quiescent Phases

    Wada Yuuki, Yuasa Takayuki, Nakazawa Kazuhiro, Makishima Kazuo, Hayashi Takayuki, Ishida Manabu

    20TH EUROPEAN WHITE DWARF WORKSHOP   509 巻   頁: 509 - 514   2017年

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  119. NuSTAR Observations of the Dwarf Nova GK Persei in 2015: Comparison between Outburst and Quiescent Phases 査読有り

    Yuuki Wada, Takayuki Yuasa, Kazuhiro Nakazawa, Kazuo Makishima, Takayuki Hayashi, Manabu Ishida

    20TH EUROPEAN WHITE DWARF WORKSHOP   509 巻   頁: 509 - 514   2017年

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    記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:ASTRONOMICAL SOC PACIFIC  

    We report on NuSTAR observations of the intermediate polar GK Persei which also behaves as a dwarf nova. It exhibited a dwarf nova outburst in 2015 March April. The object was observed in 3-79 keV X-rays with NuSTAR, once at the outburst peak, and again in 2015 September during quiescence. The 5-50 keV flux during the outburst was 26 times higher than that during the quiescence. With a multi-temperature emission model and a reflection model, we derived the post-shock temperature as 19.2 +/- 0.7 keV in the outburst, and 38.5(-3.6)(+4.1) keV in the quiescence. This temperature difference is considered to reflect changes in the radius at which the accreting matter, forming an accretion disk, is captured by the magnetosphere of the white dwarf (WD). Assuming that this radius scales as the power of -2/7 of the mass accretion rate, and utilizing the two temperature measurements, as well as the standard mass-radius relation of WDs, we determined the WD mass in GK Persei as 0.90 +/- 0.06 solar masses. The magnetic field is estimated as 4 x 10(5) G.

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  120. The status of DECIGO 査読有り

    Sato Shuichi, Kawamura Seiji, Ando Masaki, Nakamura Takashi, Tsubono Kimio, Araya Akito, Funaki Ikkoh, Ioka Kunihito, Kanda Nobuyuki, Moriwaki Shigenori, Musha Mitsuru, Nakazawa Kazuhiro, Numata Kenji, Sakai Shin-ichiro, Seto Naoki, Takashima Takeshi, Tanaka Takahiro, Agatsuma Kazuhiro, Aoyanagi Koh-suke, Arai Koji, Asada Hideki, Aso Yoichi, Chiba Takeshi, Ebisuzaki Toshikazu, Ejiri Yumiko, Enoki Motohiro, Eriguchi Yoshiharu, Fujimoto Masa-Katsu, Fujita Ryuichi, Fukushima Mitsuhiro, Futamase Toshifumi, Ganzu Katsuhiko, Harada Tomohiro, Hashimoto Tatsuaki, Hayama Kazuhiro, Hikida Wataru, Himemoto Yoshiaki, Hirabayashi Hisashi, Hiramatsu Takashi, Hong Feng-Lei, Horisawa Hideyuki, Hosokawa Mizuhiko, Ichiki Kiyotomo, Ikegami Takeshi, Inoue Kaiki T., Ishidoshiro Koji, Ishihara Hideki, Ishikawa Takehiko, Ishizaki Hideharu, Ito Hiroyuki, Itoh Yousuke, Kawashima Nobuki, Kawazoe Fumiko, Kishimoto Naoko, Kiuchi Kenta, Kobayashi Shiho, Kohri Kazunori, Koizumi Hiroyuki, Kojima Yasufumi, Kokeyama Keiko, Kokuyama Wataru, Kotake Kei, Kozai Yoshihide, Kudoh Hideaki, Kunimori Hiroo, Kuninaka Hitoshi, Kuroda Kazuaki, Maeda Kei-ichi, Matsuhara Hideo, Mino Yasushi, Miyakawa Osamu, Miyoki Shinji, Morimoto Mutsuko Y., Morioka Tomoko, Morisawa Toshiyuki, Mukohyama Shinji, Nagano Shigeo, Naito Isao, Nakamura Kouji, Nakano Hiroyuki, Nakao Kenichi, Nakasuka Shinichi, Nakayama Yoshinori, Nishida Erina, Nishiyama Kazutaka, Nishizawa Atsushi, Niwa Yoshito, Noumi Taiga, Obuchi Yoshiyuki, Ohashi Masatake, Ohishi Naoko, Ohkawa Masashi, Okada Norio, Onozato Kouji, Oohara Kenichi, Sago Norichika, Saijo Motoyuki, Sakagami Masaaki, Sakata Shihori, Sasaki Misao, Sato Takashi, Shibata Masaru, Shinkai Hisaaki, Somiya Kentaro, Sotani Hajime, Sugiyama Naoshi, Suwa Yudai, Suzuki Rieko, Tagoshi Hideyuki, Takahashi Fuminobu, Takahashi Kakeru, Takahashi Keitaro, Takahashi Ryutaro, Takahashi Ryuichi, Takahashi Tadayuki, Takahashi Hirotaka, Akiteru Takamori, Takano Tadashi, Taniguchi Keisuke, Taruya Atsushi, Tashiro Hiroyuki, Torii Yasuo, Toyoshima Morio, Tsujikawa Shinji, Tsunesada Yoshiki, Ueda Akitoshi, Ueda Ken-ichi, Utashima Masayoshi, Wakabayashi Yaka, Yamakawa Hiroshi, Yamamoto Kazuhiro, Yamazaki Toshitaka, Yokoyama Jun'ichi, Yoo Chul-Moon, Yoshida Shijun, Yoshino Taizoh

    11TH INTERNATIONAL LISA SYMPOSIUM   840 巻 ( 1 )   2017年

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    記述言語:日本語   掲載種別:研究論文(国際会議プロシーディングス)   出版者・発行元:Journal of Physics: Conference Series  

    DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) is the planned Japanese space gravitational wave antenna, aiming to detect gravitational waves from astrophysically and cosmologically significant sources mainly between 0.1 Hz and 10 Hz and thus to open a new window for gravitational wave astronomy and for the universe. DECIGO will consists of three drag-free spacecraft arranged in an equilateral triangle with 1000 km arm lengths whose relative displacements are measured by a differential Fabry-Perot interferometer, and four units of triangular Fabry-Perot interferometers are arranged on heliocentric orbit around the sun. DECIGO is vary ambitious mission, we plan to launch DECIGO in era of 2030s after precursor satellite mission, B-DECIGO. B-DECIGO is essentially smaller version of DECIGO: B-DECIGO consists of three spacecraft arranged in an triangle with 100 km arm lengths orbiting 2000 km above the surface of the earth. It is hoped that the launch date will be late 2020s for the present..

    DOI: 10.1088/1742-6596/840/1/012010

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  121. 散乱型偏光度検出器の性能向上を目指したシンチレーターの反射材の改良

    齋藤 耀, 郡司 修一, 中森 健之, 奥村 曉, 中澤 知洋, 黒澤 俊介, 渡邊 直輝, 軽部 敦人

    日本物理学会講演概要集   72.2 巻 ( 0 ) 頁: 414 - 414   2017年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.72.2.0_414

    CiNii Research

  122. Focusing on relativistic universe and cosmic evolution: The FORCE mission

    Koji Mori, Takeshi Go Tsuru, Kazuhiro Nakazawa, Yoshihiro Ueda, Takashi Okajima, Hiroshi Murakami, Hisamitsu Awaki, Hironori Matsumoto, Yasushi Fukazawa, Hiroshi Tsunemi, Tadayuki Takahashi, William W. Zhang

    Proceedings of Science     2017年

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    掲載種別:研究論文(国際会議プロシーディングス)  

    The Focusing On Relativistic universe and Cosmic Evolution (FORCE) mission is proposed as a future Japan-lead X-ray observatory to be launched in the mid 2020s. FORCE is a successor of Hitomi, focusing on the braodband X-ray imaging spectroscopy in 1–80 keV with a significantly higher angular resolution of < 15′′ in half-power diameter. The sensitivity above 10 keV will be 10 times higher than that of any previous hard X-ray missions with simultaneous soft X-ray coverage. The satellite is planned to be launched by the Epsilon vehicle by ISAS/JAXA. In the current design concept, FORCE is equipped with three identical pairs of supermirrors and wideband X-ray detectors. The focal length of the mirrors is 10 m. The silicon mirror with multi-layer coating is our primary choice of optics to achieve a good angular resolution for the wide energy band while maintaining a light weight. The detector is a hybrid of a SOI-CMOS silicon-pixel detector and a CdTe detector responsible for the softer and harder energy bands, respectively. It is basically a descendant of the hard X-ray imager onboard Hitomi with its soft-band detector replaced with the SOI-CMOS. The primary scientific objective of the FORCE mission is to trace the cosmic formation history by searching for “missing black holes” in the entire range of the mass spectrum of BHs: “buried” supermassive black holes (SMBHs) (> 104 M), intermediate-mass black holes (102–104 M), and “orphan” stellar-mass black holes (< 102 M). Also, investigation of the nature of relativistic particles at various astrophysical shocks is in our scope, with high-angular-resolution X-ray observations with the broadband coverage. FORCE will open a new era in these fields.

    Scopus

▼全件表示

書籍等出版物 3

  1. 銀河団同士の衝突による巨大衝撃波の誕生を捉えた

    加藤祐一, 中澤知洋( 担当: 共著)

    天文月報  2016年11月 

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    記述言語:日本語

  2. X 線、γ線で探る宇宙の構造と進化

    高橋忠幸, 中澤知洋( 担当: 共著)

    応用物理学会誌  2012年 

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    記述言語:日本語

  3. 宇宙科学のすばらしさを伝える

    中澤知洋,前田良知,内山泰伸,大島泰,川崎正寛,穴吹直久, 他,宇宙科学研究所X線天文グループ( 担当: 共著)

    天文月報,  2002年7月 

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    記述言語:日本語

MISC 96

  1. GRAMS:大面積液体アルゴンTPCによるMeVガンマ線観測

    丹波翼, 小高裕和, 高嶋聡, 石渡幸太, 白濱健太郎, 袴田知宏, 善本真梨那, 井上芳幸, 藤原立貴, 新井翔大, 市橋正裕, 加藤辰明, 馬場彩, 青山一天, 清水虎冴, 谷口日奈子, 中島理幾, 内海和伸, 石川皓貴, 田中雅士, 寄田浩平, 一戸悠人, 内田悠介, 大熊佳吾, 中澤知洋, KHANGULYAN Dmitry, 深沢泰司, 高橋弘充, 須田祐介, 渡辺伸, 辻直美, 広島渚, 八幡和志, 米田浩基, 荒牧嗣雄, KARAGIORGI Georgia, MUKHERJEE Reshmi  

    日本天文学会年会講演予稿集2024 巻   2024年

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  2. X線分光撮像衛星XRISMの科学運用の現状

    小川翔司, 寺田幸功, 田代信, 高橋弘充, 水野恒史, 深沢泰司, 阪本菜月, 信川正順, 宇野伸一郎, 中澤知洋, 大宮悠希, 大熊佳吾, 内山秀樹, 久保田あや, 勝田哲, 塩入匠, 寺島雄一, 志達めぐみ, 新居田祐基, 山内茂雄, 太田直美, 白木天音, 鈴木那梨, 北口貴雄, 山田智史, 坪井陽子, 米山友景, 根本登, 内田悠介, 江口智士, 谷本敦, 善本真梨那, 海老沢研, 渡辺伸, 飯塚亮, 林克洋, 内田和海, 金丸善朗, 星野晶夫, 吉田鉄生, HOLLAND Matt, YAQOOB Tahir, BALUTA Chris, LOEWENSTEIN Michael, LOEWENSTEIN Michael, MILLER Eric  

    日本天文学会年会講演予稿集2024 巻   2024年

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  3. X線分光撮像衛星XRISMの科学運用の現状

    林克洋, 田代信, 田代信, 寺田幸功, 寺田幸功, 高橋弘充, 信川正順, 水野恒史, 宇野伸一郎, 中澤知洋, 内山秀樹, 久保田あや, 寺島雄一, 深澤泰司, 山内茂雄, 太田直美, 北口貴雄, 勝田哲, 坪井陽子, 志達めぐみ, 海老沢研, 内田悠介, 江口智士, 谷本敦, 米山友景, 山田智史, 内田和海, 吉田鉄生, 金丸善朗, 小川翔司, 星野晶夫, 渡辺伸, 飯塚亮, HOLLAND Matt, LOEWENSTEIN Michael, LOEWENSTEIN Michael, MILLER Eric, YAQOOB Tahir, BALUTA Chris, 塩入匠, 阪本菜月, 白木天音, 新居田祐基, 根本登, 大宮悠希, 鈴木那梨, 善本真梨那, 大熊佳吾  

    日本物理学会講演概要集(CD-ROM)79 巻 ( 1 )   2024年

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  4. X線分光撮像衛星XRISMの時刻システム構築および軌道上精度評価

    寺田幸功, 寺田幸功, 志達めぐみ, 塩入匠, 新居田祐基, 澤田真理, 小湊隆, 田代信, 田代信, 戸田謙一, 前島弘則, 夏苅権, 高橋弘充, 信川正順, 水野恒史, 宇野伸一郎, 中澤知洋, 内山秀樹, 久保田あや, 寺島雄一, 深沢泰司, 山内茂雄, 太田直美, 北口貴雄, 勝田哲, 坪井陽子, 海老沢研, 内田悠介, 江口智士, 林克洋, 谷本敦, 米山友景, 山田智史, 内田和海, 吉田鉄生, 金丸善朗, 小川翔司, 星野晶夫, 渡辺伸, 飯塚亮, HOLLAND M, LOEWENSTEIN M, LOEWENSTEIN M, MILLER E, YAQOOB T, BALUTA C  

    日本物理学会講演概要集(CD-ROM)79 巻 ( 1 )   2024年

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  5. GRAMS実験14:ステータス報告

    小高裕和, 石渡幸太, 井上芳幸, 白濱健太郎, 高嶋聡, 田中雅士, 袴田知宏, 善本真梨那, 青山一天, 石川皓貴, 内海和伸, 清水虎冴, 谷口日奈子, 中島理幾, 寄田浩平, 新井翔大, 市橋正裕, 加藤辰明, 馬場彩, 一戸悠人, 内田悠介, 大熊佳吾, 中澤知洋, KHANGULYAN Dmitry, 須田祐介, 高橋弘充, 深沢泰司, 丹波翼, 渡辺伸, 辻直美, 広島渚, 八幡和志, 米田浩基, ARAMAKI Tsuguo, KARAGIORGI Georgia, MUKHERJEE Reshmi  

    日本物理学会講演概要集(CD-ROM)78 巻 ( 2 )   2023年

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  6. 広帯域X線の高感度観測衛星FORCE:2023年春におけるミッション提案の現状

    中澤知洋, 森浩二, 村上弘志, 赤松弘規, 久保田あや, 幸村孝由, 小林翔悟, 高橋忠幸, 馬場彩, 萩野浩一, 寺田幸功, 内山泰伸, 佐藤寿紀, 石村康生, 北山哲, 谷津陽一, 藤田裕, 石田学, 渡辺伸, 山口弘悦, 中嶋大, 古澤彰浩, 信川正順, 太田直美, 鶴剛, 上田佳宏, 榎戸輝揚, 内田裕之, 水本岬希, 信川久実子, 松本浩典, 小高裕和, 野田博文, 常深博, 田中孝明, 鈴木寛大, 伊藤真之, 粟木久光, 寺島雄一, 志達めぐみ, 深沢泰司, 水野恒史, 高橋弘充, 武田彩希, 谷本敦, HORNSCHEMEIER A.E., 岡島崇, ZHANG W.W.  

    日本物理学会講演概要集(CD-ROM)78 巻 ( 1 )   2023年

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  7. 冬季の日本海沿岸におけるガンマ線グロー領域で始まった雷放電の観測

    鶴見美和, 鶴見美和, 榎戸輝揚, 一方井祐子, 辻直希, GABRIEL Diniz, WU Ting, WANG Daohong, 高垣徹, 三宅晶子, 富岡大, 中澤知洋, 篠田太郎, 森本健志, 中村佳敬, 鴨川仁, 土屋晴文  

    日本物理学会講演概要集(CD-ROM)78 巻 ( 1 )   2023年

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  8. X線分光撮像衛星XRISMの観測データ処理ツールの開発状況

    山田智史, 田代信, 田代信, 寺田幸功, 寺田幸功, 高橋弘充, 信川正順, 水野恒史, 宇野伸一郎, 久保田あや, 中澤知洋, 渡辺伸, 飯塚亮, 佐藤理江, 林克洋, 米山友景, 吉田鉄生, BALUTA Chris, 海老沢研, 江口智士, 深澤泰司, 橋口葵, 勝田哲, 北口貴雄, 小高裕和, 大野雅功, 太田直美, 阪間美南, 阪本菜月, 志達めぐみ, 塩入匠, 丹波翼, 谷本敦, 寺島雄一, 坪井陽子, 内田和海, 内田悠介, 内山秀樹, 山内茂雄  

    日本天文学会年会講演予稿集2023 巻   2023年

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  9. X線分光撮像衛星XRISMの科学運用準備の現状(3)

    林克洋, 田代信, 寺田幸功, 高橋弘充, 信川正順, 水野恒史, 宇野伸一郎, 久保田あや, 中澤知洋, 渡辺伸, 飯塚亮, 佐藤理江, 星野晶夫, 吉田鉄生, 小川翔司, 金丸善朗, BALUTA Chris, 海老沢研, 江口智士, 小高裕和, 勝田哲, 北口貴雄, 新居田祐基, 太田直美, 阪本菜月, 志達めぐみ, 塩入匠, 白木天音, 谷本敦, 寺島雄一, 坪井陽子, 内田和海, 内田悠介, 内山秀樹, 山田智史, 山内茂雄, 米山友景  

    日本天文学会年会講演予稿集2023 巻   2023年

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  10. X線分光撮像衛星XRISMの科学運用準備の現状(2)

    米山友景, 田代信, 田代信, 寺田幸功, 寺田幸功, 高橋弘充, 信川正順, 水野恒史, 宇野伸一郎, 久保田あや, 中澤知洋, 渡辺伸, 飯塚亮, 佐藤理江, 林克洋, 吉田鉄生, BALUTA Chris, 海老沢研, 江口智士, 深澤泰司, 橋口葵, 勝田哲, 北口貴雄, 小高裕和, 大野雅功, 太田直美, 阪間美南, 阪本菜月, 志達めぐみ, 塩入匠, 丹波翼, 谷本敦, 寺島雄一, 坪井陽子, 内田和海, 内田悠介, 内山秀樹, 山田智史, 山内茂雄  

    日本天文学会年会講演予稿集2023 巻   2023年

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  11. X線分光撮像衛星XRISMの科学運用への準備状況

    内田悠介, 田代信, 田代信, 寺田幸功, 寺田幸功, 高橋弘充, 信川正順, 水野恒史, 宇野伸一郎, 久保田あや, 中澤知洋, 渡辺伸, 飯塚亮, 佐藤理江, 米山友景, 吉田鉄生, BALUTA Chris, 海老沢研, 江口智士, 深澤泰司, 橋口葵, 林克洋, 勝田哲, 北口貴雄, 小高裕和, 大野雅功, 太田直美, 阪間美南, 阪本菜月, 志達めぐみ, 塩入匠, 丹波翼, 谷本敦, 寺島雄一, 坪井陽子, 内田和海, 内山秀樹, 山田智史, 山内茂雄  

    日本物理学会講演概要集(CD-ROM)78 巻 ( 1 )   2023年

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  12. X線分光撮像衛星XRISMの科学運用に向けての模擬試験

    林克洋, 田代信, 田代信, 寺田幸功, 寺田幸功, 高橋弘充, 信川正順, 水野恒史, 宇野伸一郎, 久保田あや, 中澤知洋, 渡辺伸, 飯塚亮, 佐藤理江, 米山友景, 吉田鉄生, BALUTA Chris, 海老沢研, 江口智士, 深澤泰司, 橋口葵, 勝田哲, 北口貴雄, 小高裕和, 大野雅功, 太田直美, 阪間美南, 阪本菜月, 志達めぐみ, 塩入匠, 丹波翼, 谷本敦, 寺島雄一, 坪井陽子, 内田和海, 内田悠介, 内山秀樹, 山田智史, 山内茂雄  

    日本天文学会年会講演予稿集2023 巻   2023年

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  13. JEDI(仮)のミッションデザイン

    中澤知洋, 石田学, 内田裕之, 小高裕和, 幸村孝由, 佐藤寿紀, 澤田真理, 鈴木寛大, 高橋弘充, 田中孝明, 鶴剛, 中嶋大, 野田博文, 萩野浩一, 松本浩典, 村上弘志, 森浩二, 山口弘悦, 米山友景, 渡辺伸  

    日本天文学会年会講演予稿集2023 巻   2023年

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  14. 超新星残骸SN 1006北西部衝撃波の電子熱緩和過程の調査

    市橋正裕, 春日知明, 小高裕和, 馬場彩, 加藤佑一, 勝田哲, 鈴木寛大, 中澤知洋  

    日本天文学会年会講演予稿集2023 巻   2023年

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  15. 雷雲ガンマ線グローと下向きTGFの電子加速域の簡易的な高度測定の試み

    大口真奈里, 中澤知洋, 大熊佳吾, 大宮悠希, 安藤美唯, 田中敦也, 小林昌彦, 榎戸輝揚, 和田有希, 一方井祐子, WU Ting, WANG Daohong  

    日本物理学会講演概要集(CD-ROM)78 巻 ( 2 )   2023年

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  16. 広帯域X線の高感度観測衛星FORCE:2022年秋におけるミッション提案の現状

    中澤知洋, 森浩二, 村上弘志, 久保田あや, 小林翔悟, 幸村孝由, 高橋忠幸, 馬場彩, 小高裕和, 谷本敦, 寺田幸功, 榎戸輝揚, 内山泰伸, 佐藤寿紀, 石村康生, 北山哲, 谷津陽一, 藤田裕, 石田学, 渡辺伸, 山口弘悦, 中嶋大, 萩野浩一, 古澤彰浩, 信川正順, 太田直美, 鶴剛, 上田佳宏, 内田裕之, 水本岬希, 信川久実子, 松本浩典, 野田博文, 常深博, 田中孝明, 鈴木寛大, 伊藤真之, 粟木久光, 寺島雄一, 志達めぐみ, 深沢泰司, 水野恒史, 高橋弘充, 武田彩希, 赤松弘規, HORNSCHEMEIER A.E., 岡島崇, ZHANG W.W.  

    日本物理学会講演概要集(CD-ROM)77 巻 ( 2 )   2022年

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  17. シチズンサイエンスを活用した金沢での放射線マッピング「雷雲プロジェクト」

    榎戸輝揚, 鶴見美和, 一方井祐子, GABRIEL Diniz, 三宅晶子, 富岡大, 中澤知洋, 和田有希, 久富富平, 辻結菜, 森本健志, 中村佳敬, 鴨川仁, 沼澤正樹, 加藤陽, 湯浅孝行, 土屋晴文  

    大気電気学会誌(Web)16 巻 ( 1 )   2022年

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  18. シチズンサイエンス「雷雲プロジェクト」でのコガモ検出器による2021年度の雷雲ガンマ線の観測と解析

    鶴見美和, 鶴見美和, 榎戸輝揚, 一方井裕子, DINIZ Gabriel Sousa, 高垣徹, 三宅晶子, 富岡大, 中澤知洋, 和田有希, 篠田太郎, 森本健志, 中村佳敬, 鴨川仁, 土屋晴文  

    日本地球惑星科学連合大会予稿集(Web)2022 巻   2022年

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  19. ChandraによるSN1006北西部衝撃波の空間分解解析:重元素分布と電子温度

    市橋正裕, 春日知明, 小高裕和, 馬場彩, 加藤佑一, 勝田哲, 鈴木寛大, 中澤知洋  

    日本天文学会年会講演予稿集2022 巻   2022年

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  20. 広帯域X線の高感度観測衛星FORCE:高精度の姿勢決定系の検討と汎用天文台としての位置づけについて

    中澤知洋, 森浩二, 村上弘志, 久保田あや, 小林翔悟, 幸村孝由, 萩野浩一, 高橋忠幸, 馬場彩, 小高裕和, 寺田幸功, 榎戸輝揚, 内山泰伸, 佐藤寿紀, 石村康生, 北山哲, 谷津陽一, 藤田裕, 石田学, 渡辺伸, 山口弘悦, 中嶋大, 古澤彰浩, 信川正順, 太田直美, 鶴剛, 上田佳宏, 内田裕之, 信川久実子, 松本浩典, 野田博文, 常深博, 田中孝明, 鈴木寛大, 伊藤真之, 粟木久光, 寺島雄一, 志達めぐみ, 深沢泰司, 水野恒史, 高橋弘充, 武田彩希, 大野雅功, 赤松弘規, HORNSCHEMEIER A.E, 岡島崇, ZHANG W.W.  

    日本物理学会講演概要集(CD-ROM)77 巻 ( 1 )   2022年

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  21. 雷活動に由来するガンマ線の観測プロジェクト:コリメータ検出器で観測された3つのGamma-ray Glowの比較

    大熊佳吾, 中澤知洋, 辻結菜, 大宮悠希, 安藤美唯, 田中敦也, 大口真奈里, 榎戸輝揚, 和田有希, 湯浅孝行, 土屋晴文, 篠田太郎, DINIZ Gabriel, 山田真也, 鶴見美和, 鶴見美和, 一方井祐子  

    日本物理学会講演概要集(CD-ROM)77 巻 ( 2 )   2022年

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  22. 超小型衛星による,宇宙空間からの太陽中性子の観測(III)

    山岡和貴, 田島宏康, 宮田喜久子, 稲守孝哉, 野橋大輝, 宇佐見雅己, 中澤知洋, 増田智, 伊藤和也, 松下幸司, 高橋弘充, 渡邉恭子  

    日本天文学会年会講演予稿集2021 巻   2021年

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  23. 広帯域X線の高感度観測衛星FORCE:2020年度のミッション部および衛星システム検討の進化

    中澤知洋, 森浩二, 村上弘志, 寺田幸功, 久保田あや, 榎戸輝揚, 馬場彩, 小高裕和, 谷津陽一, 小林翔悟, 幸村孝由, 萩野浩一, 内山泰伸, 北山哲, 高橋忠幸, 石田学, 渡辺伸, 山口弘悦, 大橋隆哉, 中嶋大, 古澤彰浩, 鶴剛, 上田佳宏, 田中孝明, 内田裕之, 松本浩典, 野田博文, 常深博, 信川正順, 太田直美, 信川久実子, 伊藤真之, 粟木久光, 寺島雄一, 深沢泰司, 水野恒史, 高橋弘充, 武田彩希, 大野雅功, 赤松弘規, HORNSCHEMEIER A.E, 岡島崇, ZHANG W.W.  

    日本物理学会講演概要集(CD-ROM)76 巻 ( 1 )   2021年

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  24. 広帯域X線の高感度観測衛星FORCE:広帯域撮像検出器のサブシステム検討とCdTeイメージャ開発の現状

    中澤知洋, 森浩二, 村上弘志, 寺田幸功, 久保田あや, 榎戸輝揚, 馬場彩, 小高裕和, 谷津陽一, 小林翔悟, 幸村孝由, 萩野浩一, 内山泰伸, 佐藤寿紀, 北山哲, 高橋忠幸, 石田学, 渡辺伸, 山口弘悦, 大橋隆哉, 中嶋大, 古澤彰浩, 鶴剛, 上田佳宏, 内田裕之, 松本浩典, 野田博文, 常深博, 信川正順, 太田直美, 信川久実子, 伊藤真之, 田中孝明, 鈴木寛大, 粟木久光, 寺島雄一, 深沢泰司, 水野恒史, 高橋弘充, 武田彩希, 大野雅功, 赤松弘規, HORNSCHEMEIER A.E, 岡島崇, ZHANG W.W.  

    日本物理学会講演概要集(CD-ROM)76 巻 ( 2 )   2021年

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  25. X線衛星ChandraによるSN1006北西部衝撃波の空間分解スペクトルの解析

    市橋正裕, 春日知明, 小高裕和, 馬場彩, 加藤佑一, 勝田哲, 鈴木寛大, 中澤知洋  

    日本天文学会年会講演予稿集2021 巻   2021年

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  26. 雷雲ガンマ線のマッピング観測を狙うシチズンサイエンス「雷雲プロジェクト」の進捗

    榎戸輝揚, 一方井祐子, 和田有希, DINIZ Gabriel, 沼澤正樹, 加藤陽, 三宅晶子, 中澤知洋, 久富富平, 辻結菜, 湯浅孝行, 土屋晴文, 森本健志, 中村佳敬, 鴨川仁  

    日本地球惑星科学連合大会予稿集(Web)2021 巻   2021年

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  27. 雷雲プロジェクトの放射線検出器「コガモ」の受入試験と性能評価

    富岡大, 三宅晶子, 鶴見美和, 鶴見美和, 榎戸輝揚, 沼澤正樹, 和田有希, 中澤知洋, 一方井祐子, 高垣徹  

    電気学会東京支部茨城支所研究発表会講演予稿集29th (CD-ROM) 巻   2021年

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  28. 雷活動に関するガンマ線の観測プロジェクト:2020年1月に近接して発生した複数のロングバーストの同時途絶の観測

    久富章平, 中澤知洋, 辻結菜, 榎戸輝揚, 和田有希, 湯浅孝行, 土屋晴文, 篠田太郎, 一方井祐子, 三宅晶子  

    日本物理学会講演概要集(CD-ROM)75 巻 ( 2 )   2020年

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  29. 広帯域X線の高感度観測衛星FORCE:ミッション提案とサイエンス目的の深化

    中澤知洋, 森浩二, 鶴剛, 上田佳宏, 石田学, 松本浩典, 粟木久光, 村上弘志, 寺田幸功, 久保田あや, 榎戸輝揚, 馬場彩, 小高裕和, 谷津陽一, 小林翔悟, 幸村孝由, 萩野浩一, 内山泰伸, 北山哲, 高橋忠幸, 渡辺伸, 飯塚亮, 山口弘悦, 大橋隆哉, 中嶋大, 古澤彰浩, 田中孝明, 内田裕之, 野田博文, 常深博, 伊藤真之, 信川正順, 信川久実子, 太田直美, 寺島雄一, 深沢泰司, 水野恒史, 高橋弘充, 大野雅功, 赤松弘規, HORNSCHEMEIER A.E, 岡島崇, ZHANG W.W.  

    日本物理学会講演概要集(CD-ROM)75 巻 ( 2 )   2020年

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  30. 超小型衛星搭載用太陽中性子・ガンマ線検出器の開発

    野橋大輝, 山岡和貴, 田島宏康, 宮田喜久子, 稲守孝哉, PARK Ji Hyun, 中澤知洋, 増田智, 伊藤和也, 松下幸司, 高橋弘充, 渡邉恭子  

    日本物理学会講演概要集(CD-ROM)75 巻 ( 1 )   2020年

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  31. 雷活動に由来するガンマ線の観測プロジェクト:2019年度の多地点観測の進展

    久富章平, 中澤知洋, 辻結菜, FABIANI Alexia, 榎戸輝揚, 和田有希, 和田有希, 湯浅孝行, 古田禄大, 土屋晴文, 一方井祐子, 三宅晶子  

    日本地球惑星科学連合大会予稿集(Web)2020 巻   2020年

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  32. 雷活動に由来するガンマ線の観測プロジェクト:2019年度の多地点観測の進展

    久富章平, 中澤知洋, 辻結菜, FABIANI Alexia, 榎戸輝揚, 和田有希, 和田有希, 湯浅孝行, 古田禄大, 土屋晴文, 一方井祐子, 三宅晶子  

    日本物理学会講演概要集(CD-ROM)75 巻 ( 1 )   2020年

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  33. 雷活動に由来するガンマ線の観測プロジェクト:モニタリングポストによる2014年12月に観測されたロングバーストの長距離追跡

    辻結菜, 中澤知洋, 久富章平, 榎戸輝揚, 和田有希, 湯浅孝行, 古田禄大, 土屋晴文, 楳本大悟, 篠田太郎, 加藤雅也  

    日本物理学会講演概要集(CD-ROM)75 巻 ( 2 )   2020年

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  34. 雷活動に由来するガンマ線の観測プロジェクト:モニタリングポストを組み合わせたロングバーストの長距離追跡

    辻結菜, 中澤知洋, 久富章平, FABIANI Alexia, 榎戸輝揚, 和田有希, 和田有希, 湯浅考行, 古田禄大, 土屋晴文, 楳本大悟, 篠田太郎, 加藤雅也  

    日本地球惑星科学連合大会予稿集(Web)2020 巻   2020年

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  35. 世界最高感度を実証した「ひとみ」搭載の硬X線撮像検出器HXI

    中澤知洋, 萩野浩一  

    日本天文学会誌 天文月報112 巻   頁: 471 - 473   2019年7月

  36. 雷活動に由来するガンマ線の観測プロジェクト:多地点観測の進展と大気電場・電波との協同観測

    和田有希, 和田有希, 榎戸輝揚, 松元崇弘, 中澤知洋, 古田禄大, 湯浅孝行, 鴨川仁, BOWERS G. S, 中村佳敬, 森本健志, 玉川徹, 牧島一夫, 牧島一夫, 土屋晴文, 久保守, 松木篤, 米徳大輔, 澤野達哉, SMITH D. M  

    日本物理学会講演概要集(CD-ROM)74 巻 ( 1 ) 頁: ROMBUNNO.14aK407‐11   2019年3月

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    記述言語:日本語  

    J-GLOBAL

  37. 冬季の雷放電と同期したガンマ線フラッシュの定量評価

    和田有希, 和田有希, 榎戸輝揚, 中澤知洋, 古田禄大, 湯浅孝行, 中村佳敬, 森本健志, 松元崇弘, 牧島一夫, 牧島一夫, 土屋晴文  

    日本原子力学会春の年会予稿集(CD-ROM)2019 巻   頁: ROMBUNNO.1H07   2019年3月

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    記述言語:日本語  

    J-GLOBAL

  38. 冬季雷における高エネルギー現象の観測プロジェクトの進展

    和田有希, 和田有希, 榎戸輝揚, 松元崇弘, 中澤知洋, 古田禄大, 湯浅孝行, 土屋晴文, 米徳大輔, 澤野達哉, 牧島一夫, 牧島一夫, 鴨川仁, 中村佳敬, 森本健志, 佐藤光輝, 酒井英男, 南戸秀仁, 牛尾知雄  

    日本地球惑星科学連合大会予稿集(Web)2019 巻   頁: ROMBUNNO.MIS27‐10 (WEB ONLY)   2019年

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    記述言語:日本語  

    J-GLOBAL

  39. 超小型衛星による,宇宙空間からの太陽中性子の観測(III)

    山岡和貴, 田島宏康, 宮田喜久子, 稲守孝哉, PARK Ji Hyun, 野橋大輝, 中澤知洋, 増田智, 伊藤和也, 松下幸司, 高橋弘充, 渡邉恭子  

    日本天文学会年会講演予稿集2019 巻   2019年

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  40. 3Uキューブサットによる太陽中性子・ガンマ線観測

    山岡和貴, 田島宏康, 宮田喜久子, 稲守孝哉, 佐々井義矩, 中澤知洋, 増田智, 松下幸司, 伊藤和也, 高橋弘充, 渡邉恭子  

    日本地球惑星科学連合大会予稿集(Web)2019 巻   2019年

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  41. 超小型衛星による,宇宙空間からの太陽中性子の観測(II)

    山岡和貴, 田島宏康, 佐々井義矩, 宮田喜久子, 稲守孝哉, 中澤知洋, 増田智, 伊藤和也, 松下幸司, 高橋弘充, 渡邉恭子  

    日本天文学会年会講演予稿集2019 巻   2019年

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  42. Detection of polarized gamma-ray emission from the Crab nebula with Hitomi Soft Gamma-ray Detector

    Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu, Fumie Akimoto, Steven W. Allen, Lorella Angelini, Marc Audard, Hisamitsu Awaki, Magnus Axelsson, Aya Bamba, Marshall, W. Bautz, Roger Blandford, Laura W. Brenneman, Gregory V. Brown, Esra Bulbul, Edward M. Cackett, Maria Chernyakova, Meng P. Chiao, Paolo S. Coppi, Elisa Costantini, Jelle de Plaa, Cor P. de Vries, Jan-Willem den Herder, Chris Done, Tadayasu Dotani, Ken Ebisawa, Megan E. Eckart, Teruaki Enoto, Yuichiro Ezoe, Andrew C. Fabian, Carlo Ferrigno, Adam R. Foster, Ryuichi Fujimoto, Yasushi Fukazawa, Akihiro Furuzawa, Massimiliano Galeazzi, Luigi C. Gallo, Poshak Gandhi, Margherita Giustini, Andrea Goldwurm, Liyi Gu, Matteo Guainazzi, Yoshito Haba, Kouichi Hagino, Kenji Hamaguchi, Ilana M. Harrus, Isamu Hatsukade, Katsuhiro Hayashi, Takayuki Hayashi, Kiyoshi Hayashida, Junko S. Hiraga, Ann Hornschemeier, Akio Hoshino, John, P. Hughes, Yuto Ichinohe, Ryo Iizuka, Hajime Inoue, Yoshiyuki Inoue, Manabu Ishida, Kumi Ishikawa, Yoshitaka Ishisaki, Masachika Iwai, Jelle Kaastra, Tim Kallman, Tsuneyoshi Kamae, Jun Kataoka, Satoru Katsuda, Nobuyuki Kawai, Richard L. Kelley, Caroline A. Kilbourne, Takao Kitaguchi, Shunji Kitamoto, Tetsu Kitayama, Takayoshi Kohmura, Motohide Kokubun, Katsuji Koyama, Shu Koyama, Peter Kretschmar, Hans A. Krimm, Aya Kubota, Hideyo Kunieda, Philippe Laurent, Shiu-Hang Lee, Maurice A. Leutenegger, Olivier Limousin, Michael Loewenstein, Knox S. Long, David Lumb, Greg Madejski, Yoshitomo Maeda, Daniel Maier, Kazuo Makishima, Maxim Markevitch, Hironori Matsumoto, Kyoko Matsushita, Dan McCammon, Brian R. McNamara, Missagh Mehdipour, Eric D. Miller, Jon M. Miller, Shin Mineshige, Kazuhisa Mitsuda, Ikuyuki Mitsuishi, Takuya Miyazawa, Tsunefumi Mizuno, Hideyuki Mori, Koji Mori, Koji Mukai, Hiroshi Murakami, Richard, F. Mushotzky, Takao Nakagawa, Hiroshi Nakajima, Takeshi Nakamori, Shinya Nakashima, Kazuhiro Nakazawa, Kumiko K. Nobukawa, Masayoshi Nobukawa, Hirofumi Noda, Hirokazu Odaka, Takaya Ohashi, Masanori Ohno, Takashi Okajima, Naomi Ota, Masanobu Ozaki, Frits Paerels, Stephane Paltani, Robert Petre, Ciro Pinto, Frederick S. Porter, Katja Pottschmidt, Christopher S. Reynolds, Samar Safi-Harb, Shinya Saito, Kazuhiro Sakai, Toru Sasaki, Goro Sato, Kosuke Sato, Rie Sato, Makoto Sawada, Norbert Schartel, Peter J. Serlemtsos, Hiromi Seta, Megumi Shidatsu, Aurora Simionescu, Randall K. Smith, Yang Soong, Lukasz Stawarz, Yasuharu Sugawara, Satoshi Sugita, Andrew Szymkowiak, Hiroyasu Tajima, Hiromitsu Takahashi, Tadayuki Takahashi, Shin'ichiro Takeda, Yoh Takei, Toru Tamagawa, Takayuki Tamura, Takaaki Tanaka, Yasuo Tanaka, Yasuyuki T. Tanaka, Makoto S. Tashiro, Yuzuru Tawara, Yukikatsu Terada, Yuichi Terashima, Francesco Tombesi, Hiroshi Tomida, Yohko Tsuboi, Masahiro Tsujimoto, Hiroshi Tsunemi, Takeshi Go Tsuru, Hiroyuki Uchida, Hideki Uchiyama, Yasunobu Uchiyama, Shutaro Ueda, Yoshihiro Ueda, Shin'ichiro Uno, C. Megan Urry, Eugenio Ursino, Shin Watanabe, Norbert Werner, Dan R. Wilkins, Brian J. Williams, Shinya Yamada, Hiroya Yamaguchi, Kazutaka Yamaoka, Noriko Y. Yamasaki, Makoto Yamauchi, Shigeo Yamauchi, Tahir Yaqoob, Yoichi Yatsu, Daisuke Yonetoku, Irina Zhuravleva, Abderahmen Zoghbi, Yuusuke Uchida  

    日本物理学会講演概要集73 巻   頁: 492 - 492   2018年10月

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    記述言語:日本語   掲載種別:機関テクニカルレポート,技術報告書,プレプリント等   出版者・発行元:一般社団法人 日本物理学会  

    We present the results from the Hitomi Soft Gamma-ray Detector (SGD)<br />
    observation of the Crab nebula. The main part of SGD is a Compton camera, which<br />
    in addition to being a spectrometer, is capable of measuring polarization of<br />
    gamma-ray photons. The Crab nebula is one of the brightest X-ray / gamma-ray<br />
    sources on the sky, and, the only source from which polarized X-ray photons<br />
    have been detected. SGD observed the Crab nebula during the initial test<br />
    observation phase of Hitomi. We performed the data analysis of the SGD<br />
    observation, the SGD background estimation and the SGD Monte Carlo simulations,<br />
    and, successfully detected polarized gamma-ray emission from the Crab nebula<br />
    with only about 5 ks exposure time. The obtained polarization fraction of the<br />
    phase-integrated Crab emission (sum of pulsar and nebula emissions) is (22.1<br />
    $\pm$ 10.6)% and, the polarization angle is 110.7$^o$ + 13.2 / $-$13.0$^o$ in<br />
    the energy range of 60--160 keV (The errors correspond to the 1 sigma<br />
    deviation). The confidence level of the polarization detection was 99.3%. The<br />
    polarization angle measured by SGD is about one sigma deviation with the<br />
    projected spin axis of the pulsar, 124.0$^o$ $\pm$0.1$^o$.

    DOI: 10.11316/jpsgaiyo.73.1.0_492

    arXiv

  43. 炭素繊維強化プラスチック(CFRP)へのX線反射面形成法の開発

    粟木久光, 大上千智, 吉田鉄生, 岩切駿, 相田望, 松本浩典, 三石郁之, 大塚康司, 清水貞行, 田村啓輔, 中澤知洋, 石田学, 石田直樹  

    日本天文学会年会講演予稿集2018 巻   頁: 227   2018年8月

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    記述言語:日本語  

    J-GLOBAL

  44. 銀河面からの軟X線背景放射(5)

    石原雅士, 三石郁之, 中澤知洋  

    日本天文学会年会講演予稿集2018 巻   頁: 156   2018年8月

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    記述言語:日本語  

    J-GLOBAL

  45. 軟X線から硬X線の広帯域を高感度で撮像分光する小型衛星計画FORCEの現状(7)

    中澤知洋, 森浩二, 鶴剛, 上田佳宏, 松本浩典, 粟木久光, 石田学, 寺島雄一, 常深博, 中嶋大, 田中孝明, 内田裕之, 伊藤真之, 寺田幸功, 久保田あや, 馬場彩, 小高裕和, 高橋忠幸, 谷津陽一, 幸村孝由, 萩野浩一, 小林翔悟, 北山哲, 村上弘志, 信川正順, 太田直美, 深沢泰司, 水野恒史, 高橋弘充, 大野雅功, 古澤彰浩, 武田彩希, 中島真也, 内山泰伸, 渡辺伸, 飯塚亮, 岡島崇, 山口弘悦, 森英之  

    日本天文学会年会講演予稿集2018 巻   頁: 220   2018年8月

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    記述言語:日本語  

    J-GLOBAL

  46. Discovery of recombining plasma from the faintest GeV SNR HB 21 and a possible scenario of the cosmic ray escaping from SNR shocks

    Hiromasa Suzuki, Aya Bamba, Kazuhiro Nakazawa, Yoshihiro Furuta, Makoto Sawada, Ryo Yamazaki, Katsuji Koyama  

      70 巻 ( 4 )   2018年5月

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    記述言語:英語   掲載種別:機関テクニカルレポート,技術報告書,プレプリント等  

    We present an X-ray study of the GeV gamma-ray supernova remnant (SNR) HB 21<br />
    with Suzaku. HB 21 is interacting with molecular clouds and the faintest in the<br />
    GeV band among known GeV SNRs. We discovered strong radiative recombination<br />
    continua of Si and S from the center of the remnant, which provide the direct<br />
    evidence of a recombining plasma (RP). The total emission can be explained with<br />
    the RP and ionizing plasma components. The electron temperature and<br />
    recombination timescale of the RP component were estimated as 0.17 (0.15-0.18)<br />
    keV and 3.2 (2.0-4.8) $\times$ 10$^{11}$ s cm$^{-3}$, respectively. The<br />
    estimated age of the RP (RP age; $\sim$ 170 kyr) is the longest among known<br />
    recombining GeV SNRs, because of very low density of electrons ($\sim$ 0.05<br />
    cm$^{-3}$). We have examined dependencies of GeV spectral indices on each of RP<br />
    ages and SNR diameters for nine recombining GeV SNRs. Both showed possible<br />
    positive correlations, indicating that both the parameters can be good<br />
    indicators of properties of accelerated protons, for instance, degree of escape<br />
    from the SNR shocks. A possible scenario for a process of proton escape is<br />
    introduced; interaction with molecular clouds makes weaker magnetic turbulence<br />
    and cosmic-ray protons escape, simultaneously cooling down the thermal<br />
    electrons and generate an RP.

    DOI: 10.1093/pasj/psy069

    Web of Science

    arXiv

  47. X線衛星「ひとみ」搭載軟ガンマ線検出器(SGD)によるかに星雲のガンマ線偏光観測

    渡辺伸, 渡辺伸, 内田悠介, 内田悠介, 田島宏康, 深沢泰司, 一戸悠人, 内山秀樹, 内山泰伸, 榎戸輝揚, 太田方之, 大野雅功, 小高裕和, 片岡淳, 勝田隼一郎, 北口貴雄, 国分紀秀, GOLDWURM A, 斉藤新也, 佐藤悟朗, 佐藤理江, 高橋忠幸, 高橋忠幸, 高橋弘充, 武田伸一郎, 田中孝明, 田中康之, 寺田幸功, 中澤知洋, 中澤知洋, 中野俊男, 中森健之, 野田博文, 萩野浩一, 林克洋, 林克洋, BLANDFORD R, 牧島一夫, MADEJSKI G, 水野恒史, 森國城, 谷津陽一, 山岡和貴, 湯浅孝行, 米徳大輔, LAURENT P, LIMOUSIN O, LEBRUN F  

    日本物理学会講演概要集(CD-ROM)73 巻 ( 1 ) 頁: ROMBUNNO.25pK307‐5   2018年3月

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    記述言語:日本語  

    J-GLOBAL

  48. 大型CsI結晶を用いた冬季雷雲由来ガンマ線検出器の量産とそれを用いたマッピング観測

    松元崇弘, 和田有希, 和田有希, 古田禄大, 清野愛海, 中澤知洋, 中澤知洋, 榎戸輝揚, 湯浅孝行, 牧島一夫, 中野俊男, 土屋晴文  

    日本物理学会講演概要集(CD-ROM)73 巻 ( 1 ) 頁: ROMBUNNO.22aK307‐7 - 414   2018年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.1.0_414

    CiNii Research

    J-GLOBAL

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    榎戸輝揚, 和田有希, 和田有希, 古田禄大, 中澤知洋, 湯浅孝行, 奥田和史, 牧島一夫, 佐藤光輝, 佐藤陽祐, 中野俊男, 楳本大悟, 土屋晴文, 土屋晴文  

    日本物理学会講演概要集(CD-ROM)73 巻 ( 1 ) 頁: ROMBUNNO.22pK305‐7 - 176   2018年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.1.0_176

    CiNii Research

    J-GLOBAL

  50. 落雷による光核反応の発見:地上観測による中性子と陽電子の検出

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    日本物理学会講演概要集(CD-ROM)73 巻 ( 1 ) 頁: ROMBUNNO.22aK308‐7 - 422   2018年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.1.0_422

    CiNii Research

    J-GLOBAL

  51. 落雷による光核反応の発見:シミュレーションによるデータ解釈

    古田禄大, 和田有希, 和田有希, 榎戸輝揚, 中澤知洋, 湯浅孝行, 奥田和史, 牧島一夫, 佐藤光輝, 佐藤陽祐, 中野俊男, 楳本大悟, 土屋晴文  

    日本物理学会講演概要集(CD-ROM)73 巻 ( 1 ) 頁: ROMBUNNO.22aK308‐8 - 423   2018年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.73.1.0_423

    J-GLOBAL

  52. 日本海沿岸における冬の雷や雷雲に伴う放射線観測

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    日本原子力学会春の年会予稿集(CD-ROM)2018 巻   頁: ROMBUNNO.3E01   2018年3月

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    J-GLOBAL

  53. GRB位置決定のための小型衛星搭載用大型CsIシンチレータのMPPC読み出し性能評価

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    日本天文学会年会講演予稿集2018 巻   頁: 239   2018年2月

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    J-GLOBAL

  54. 「ひとみ」HXIを用いた軌道上中性子バックグラウンドの評価

    鈴木寛大, 中澤知洋, 萩野浩一, 国分紀秀, 佐藤悟朗, 高橋忠幸, 渡辺伸, 太田方之, 佐藤理江, 森國城, 村上浩章, 三宅克馬, 古田禄大, 馬場彩, 鶴剛, 田中孝明, 榎戸輝揚, 小林翔悟, 寺田幸功, 内山秀樹, 谷津洋一, 野田博文, 田島宏康, 山岡和貴, 林克洋, 林克洋, 深沢泰司, 水野恒史, 大野雅功, 高橋弘充, 勝田隼一郎, 中森健之, 内山泰伸, 斉藤新也, 牧島一夫, 小高裕和, 湯浅孝行, 中野俊男, 片岡淳, 三村健人, LEBRUN Francois, LIMOUSIN Olivier, LAURENT Philippe, MAIER Daniel, 武田伸一郎, 森浩二  

    日本天文学会年会講演予稿集2018 巻   頁: 227   2018年2月

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  55. X線衛星代替機XARMにおける科学運用計画

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    日本天文学会年会講演予稿集2018 巻   頁: 228   2018年2月

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    J-GLOBAL

  56. X線天文衛星「ひとみ」搭載SGDによるかに星雲からの偏光ガンマ線の観測

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    日本天文学会年会講演予稿集2018 巻   頁: 148   2018年2月

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  57. X線を用いたKepler超新星残骸中のFeの非等方な膨張構造解析

    春日知明, 佐藤寿紀, 佐藤寿紀, 森浩二, 山口弘悦, 山口弘悦, 馬場彩, 中澤知洋  

    日本天文学会年会講演予稿集2018 巻   頁: 71   2018年2月

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  58. 地上と宇宙から探る雷放電に同期する突発ガンマ線観測への取り組み

    中澤知洋, 榎戸輝揚, 和田有希, 和田有希, 古田禄大, 松元崇弘, 春日知明, 奥田和史, 湯浅孝行, 中野俊男, 楳本大悟, 加藤博, 牧島一夫, 佐藤光輝, 佐藤陽祐, 土屋晴文  

    日本天文学会年会講演予稿集2018 巻   頁: 240   2018年2月

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  59. 重力波対応天体の追観測を目指した超小型GRB観測衛星における位置決定精度の評価

    田中晃司, 深沢泰司, 水野恒史, 高橋弘充, 大野雅功, 内田和海, 鳥越健斗, WERNER Norbert, WERNER Norbert, WERNER Norbert, PAL Andras, FREI Zsolt, KISS Laszlo, NORBERT Tarcai, 中澤知洋, 榎戸輝揚, 小高裕和, 一戸悠人  

    日本天文学会年会講演予稿集2018 巻   頁: 239   2018年2月

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    J-GLOBAL

  60. 軟X線から硬X線の広帯域を高感度で撮像分光する小型衛星計画FORCEの現状(6)

    森浩二, 武田彩希, 村上弘志, 寺田幸功, 久保田あや, 中澤知洋, 馬場彩, 谷津陽一, 幸村孝由, 萩野浩一, 小高裕和, 中島真也, 内山泰伸, 斉藤新也, 北山哲, 高橋忠幸, 石田学, 渡辺伸, 飯塚亮, 古澤彰浩, 鶴剛, 上田佳宏, 田中孝明, 内田裕之, 小林翔悟, 松本浩典, 中嶋大, 常深博, 信川正順, 太田直美, 伊藤真之, 粟木久光, 寺島雄一, 深沢泰司, 水野恒史, 高橋弘充, 大野雅功, 岡島崇, 山口弘悦, 森英之  

    日本天文学会年会講演予稿集2018 巻   頁: 231   2018年2月

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  61. 狭輝線I型セイファート銀河Swift J2127.4+5654におけるディレイとハード一次成分

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    日本天文学会年会講演予稿集2018 巻   頁: 171   2018年2月

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  62. GROWTH実験2014年度データを用いた雷雲ガンマ線イベントの探索法の改善

    楳本大悟, 土屋晴文, 中澤知洋, 湯浅孝行, 榎戸輝揚, 牧島一夫, 古田禄大, 玉川徹, 伊藤伸泰  

    日本物理学会講演概要集(CD-ROM)72 巻 ( 2 ) 頁: ROMBUNNO.13pU32‐6   2017年9月

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    J-GLOBAL

  63. モンテカルロシミュレーションによる雷雲ガンマ線放射モデルの構築

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    日本物理学会講演概要集(CD-ROM)72 巻 ( 2 ) 頁: ROMBUNNO.15aU33‐4 - 412   2017年9月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.72.2.0_412

    J-GLOBAL

  64. 散乱型偏光度検出器の性能向上を目指したシンチレーターの反射材の改良

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    日本物理学会講演概要集(CD-ROM)72 巻 ( 2 ) 頁: ROMBUNNO.15aU33‐6   2017年9月

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    J-GLOBAL

  65. 雷雲ガンマ線の地上観測の現状と2017年のGROWTH実験計画

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    日本物理学会講演概要集(CD-ROM)72 巻 ( 2 ) 頁: ROMBUNNO.15aU33‐5 - 413   2017年9月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    DOI: 10.11316/jpsgaiyo.72.2.0_413

    J-GLOBAL

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    日本天文学会年会講演予稿集2017 巻   頁: 262   2017年8月

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  67. 分子雲衝突に起因する超新星残骸からの宇宙線逃亡シナリオの観測的検証

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    日本天文学会年会講演予稿集2017 巻   頁: 148   2017年8月

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  68. 「ひとみ(ASTRO‐H)」搭載軟ガンマ線検出器における軌道上バックグラウンドの理解

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    日本天文学会年会講演予稿集2017 巻   頁: 246   2017年8月

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  69. 「すざく」によるKepler超新星残骸の膨張速度測定

    春日知明, 馬場彩, 中澤知洋, 佐藤寿紀  

    日本天文学会年会講演予稿集2017 巻   頁: 147   2017年8月

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    J-GLOBAL

  70. 多波長観測から迫る銀河団RXC J1053.7+5453の衝突過程と粒子加速

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    日本天文学会年会講演予稿集2017 巻   頁: 186   2017年8月

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  71. 銀河団衝突で発生した若い衝撃波の観測研究

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    日本天文学会年会講演予稿集2017 巻   頁: 186   2017年8月

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  72. 銀河団中心部でのプラズマの二温度構造:「ひとみ」の測定結果の意義

    牧島一夫, 中島真也, GU Lily, 川原田円, 中澤知洋  

    日本天文学会年会講演予稿集2017 巻   頁: 184   2017年8月

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    J-GLOBAL

  73. 軟X線から硬X線の広帯域を高感度で撮像分光する小型衛星計画FORCEの現状(5)

    森浩二, 武田彩希, 村上弘志, 寺田幸功, 久保田あや, 中澤知洋, 馬場彩, 谷津陽一, 幸村孝由, 萩野浩一, 小高裕和, 中島真也, 内山泰伸, 斉藤新也, 北山哲, 高橋忠幸, 石田学, 渡辺伸, 飯塚亮, 古澤彰浩, 鶴剛, 上田佳宏, 田中孝明, 内田裕之, 小林翔悟, 松本浩典, 中嶋大, 常深博, 信川正順, 太田直美, 粟木久光, 寺島雄一, 深沢泰司, 水野恒史, 高橋弘充, 大野雅功, 岡島崇, 山口弘悦, 森英之  

    日本天文学会年会講演予稿集2017 巻   頁: 242   2017年8月

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  74. 矮新星GK PerseiのX線スペクトル解析による白色矮星質量の推定

    和田有希, 和田有希, 湯浅孝行, 中澤知洋, 牧島一夫, 林多佳由, 林多佳由, 石田学  

    日本天文学会年会講演予稿集2017 巻   頁: 275   2017年8月

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  75. 狭輝線I型セイファート銀河NGC4051における一次放射成分の時間変動

    三宅克馬, 野田博文, 山田真也, 清野愛海, 中澤知洋, 牧島一夫  

    日本天文学会年会講演予稿集2017 巻   頁: 175   2017年8月

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  76. 将来の硬X線・ガンマ線衛星に向けたシンチレータ反射材の改良

    清野愛海, 奥田和史, 中澤知洋, 奥村曉, 郡司修一, 牧島一夫  

    日本天文学会年会講演予稿集2017 巻   頁: 242   2017年8月

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  77. 1‐80keVの広帯域X線を高感度で撮像分光する次世代の小型科学衛星計画FORCE:2017年のステータス

    中澤知洋, 森浩二, 村上弘志, 久保田あや, 寺田幸功, 谷津陽一, 馬場彩, 幸村孝由, 内山泰伸, 斉藤新也, 北山哲, 高橋忠幸, 渡辺伸, 中島真也, 萩野浩一, 松本浩典, 古澤彰浩, 鶴剛, 上田佳宏, 田中孝明, 内田裕之, 武田彩希, 常深博, 中嶋大, 信川正順, 太田直美, 粟木久光, 寺島雄一, 深沢泰司, 高橋弘充, 大野雅功, 岡島崇, 山口弘悦, 森英之, 小高裕和  

    日本物理学会講演概要集(CD-ROM)72 巻 ( 1 ) 頁: ROMBUNNO.20aK21‐5 - 508   2017年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    <p>NGHXTあらため、FORCE衛星は1-80 keVの広帯域X線を高感度で撮像分光し、まだ見ぬ隠されたブラックホールや超新星残骸のフィラメントでの粒子加速の探査を目指している。2016年に変更した計画の内容、検出器および望遠鏡の開発状況、およびサイエンス検討の進捗を報告する。</p>

    DOI: 10.11316/jpsgaiyo.72.1.0_508

    J-GLOBAL

  78. GROWTH実験:モンテカルロシミュレーションを用いた,雷雲ガンマ線放射の広がりの解釈

    古田禄大, 楳本大悟, 中澤知洋, 奥田和史, 和田有希, 榎戸輝揚, 湯浅孝行, 土屋晴文, 牧島一夫  

    日本物理学会講演概要集(CD-ROM)72 巻 ( 1 ) 頁: ROMBUNNO.19pK41‐8 - 500   2017年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    <p>我々は雷雲内の粒子加速機構の解明を目指し,新潟県柏崎刈羽原発内で雷雲由来ガンマ線の測定を継続している。2014–15年冬には約100秒間に10万カウント前後という高統計のガンマ線増大現象が複数観測され,地上に届くガンマ線放射の広がりの大きさや形状が判明した。本講演ではモンテカルロシミュレーションを用いて,電場加速された電子が地上にもたらす制動放射ガンマ線の分布をモデル化し,実データと比較することで,加速現場の高度や加速方向の広がりを推定する。</p>

    DOI: 10.11316/jpsgaiyo.72.1.0_500

    J-GLOBAL

  79. GROWTH実験:コリメーターを用いた雷雲由来ガンマ線の角度分布の測定

    奥田和史, 中澤知洋, 古田禄大, 和田有希, 湯浅孝行, 榎戸輝揚, 鈴木寛大, 楳本大悟, 土屋晴文, 牧島一夫  

    日本物理学会講演概要集(CD-ROM)72 巻 ( 1 ) 頁: ROMBUNNO.19pK41‐9 - 501   2017年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    <p>我々は10年にわたり新潟県柏崎刈羽原発内に検出器を設置して雷雲由来のガンマ線を測定し,雷雲内の粒子加速機構の解明を目指してきた。本年度、我々はコリメーターを用いることで方向に対し感度を持つ検出器を新たに設置した。本講演ではその運用成果について報告する。</p>

    DOI: 10.11316/jpsgaiyo.72.1.0_501

    J-GLOBAL

  80. GROWTH実験:10年間の継続観測に基づく冬季雷雲由来ガンマ線の研究

    楳本大悟, 土屋晴文, 土屋晴文, 榎戸輝揚, 湯浅孝行, 古田禄大, 奥田和史, 和田有希, 玉川徹, 岡野眞治, 川原田円, 北口貴雄, 岩田憲一, 加藤博, 国分紀秀, 牧島一夫, 牧島一夫, 中澤知洋  

    日本物理学会講演概要集(CD-ROM)72 巻 ( 1 ) 頁: ROMBUNNO.19pK41‐7 - 499   2017年3月

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    <p>我々はこれまで10年にわたり新潟県柏崎刈羽原発内に検出器を設置して雷雲由来のガンマ線を観測し、放射機構の解明を目指してきた。2014,2015年に観測された事象の空間分布を調べたところ、強度変動の主原因が雷雲の移動で、放射が到達した領域が1 kmスケールの楕円であることが確定し、2分程度にわたり放射が持続したことも判明した。これに基づき、これまで観測された全事象について系統的なスペクトル・カウント数の時系列解析を行った。</p>

    DOI: 10.11316/jpsgaiyo.72.1.0_499

    J-GLOBAL

  81. 長周期の連星X線パルサーは10<sup>13</sup>Gの超強磁場をもつか?

    牧島一夫, 高木利紘, 高木利紘, 笹野理, 三原建弘, 杉崎睦, 谷田部史尭, 谷田部史尭, 中島基樹, 中澤知洋  

    日本物理学会講演概要集(CD-ROM)72 巻 ( 1 ) 頁: ROMBUNNO.17pK41‐8   2017年3月

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    記述言語:日本語  

    J-GLOBAL

  82. GeVガンマ線超新星残骸HB21のX線観測による過電離プラズマの発見

    鈴木寛大, 馬場彩, 中澤知洋, 澤田真理, 小山勝二  

    日本天文学会年会講演予稿集2017 巻   頁: 141   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  83. すざく衛星によるTriangulum Australis銀河団の超高温領域と非熱的X線放射の探査

    鷹箸颯太, 滝沢元和, 板花まどか, 中澤知洋  

    日本天文学会年会講演予稿集2017 巻   頁: 190   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  84. 「すざく」を用いたLMXBのスペクトル状態遷移の研究 II

    小野光, 牧島一夫, ZHANG Zhongli, 中澤知洋  

    日本天文学会年会講演予稿集2017 巻   頁: 259   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  85. 「すざく」で観測した近傍銀河団・銀河群のエントロピー分布

    佐々木亨, 松下恭子, 佐藤浩介, 横田佳奈, 栗山翼, 菅野祐, 赤松弘規, 藤田裕, 中澤知洋, 岡部信広, 大橋隆哉, 太田直美, 田村隆幸, 滝沢元和  

    日本天文学会年会講演予稿集2017 巻   頁: 186   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  86. SWIFT J2127.4+5654における時間変動を用いたモデル依存しない成分分解

    三宅克馬, 野田博文, 山田真也, 清野愛海, 中澤知洋, 牧島一夫  

    日本天文学会年会講演予稿集2017 巻   頁: 179   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  87. 狭輝線1型セイファート銀河NGC 4051のX線時間変動解析 II

    清野愛海, 野田博文, 三宅克馬, 中澤知洋, 牧島一夫  

    日本天文学会年会講演予稿集2017 巻   頁: 180   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  88. 長周期X線パルサーX Perseiが>10<sup>13</sup>Gの超強磁場をもつ可能性

    牧島一夫, 高木利紘, 三原建弘, 杉崎睦, 谷田部史尭, 笹野理, 中澤知洋, 中島基樹  

    日本天文学会年会講演予稿集2017 巻   頁: 250   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  89. 軟X線から硬X線の広帯域を高感度で撮像分光する小型衛星計画FORCEの現状(4)

    森浩二, 村上弘志, 寺田幸功, 久保田あや, 中澤知洋, 馬場彩, 谷津陽一, 幸村孝由, 内山泰伸, 斉藤新也, 北山哲, 高橋忠幸, 渡辺伸, 中島真也, 萩野浩一, 松本浩典, 古澤彰浩, 鶴剛, 上田佳宏, 田中孝明, 内田裕之, 武田彩希, 常深博, 中嶋大, 信川正順, 太田直美, 粟木久光, 寺島雄一, 深沢泰司, 高橋弘充, 大野雅功, 岡島崇, 山口弘悦, 森英之, 小高裕和  

    日本天文学会年会講演予稿集2017 巻   頁: 233   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  90. 超新星残骸SN1006における衝撃波直下での電子加熱と電離速度

    加藤佑一, 勝田哲, 馬場彩, 中澤知洋  

    日本天文学会年会講演予稿集2017 巻   頁: 55   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  91. 衝突銀河団CIZA J1358.9‐4750領域の広がった電波放射の探査

    赤堀卓也, 加藤佑一, 中澤知洋, 小澤武揚, GU Lyli, 滝沢元和, 藤田裕, 中西裕之, 岡部信弘, 牧島一夫  

    日本天文学会年会講演予稿集2017 巻   頁: 190   2017年2月

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    記述言語:日本語  

    J-GLOBAL

  92. 「ひとみ」搭載硬X線・軟ガンマ線帯観測装置の軌道上性能

    粟木 久光, 松本 浩典, 石田 学, 中澤 知洋, 国分 紀秀, 田島 宏康, 深沢 泰司, 渡辺 伸, 幅 良統, 飯塚 亮, 太田 方之, 佐藤 理江, 高橋 忠幸, 萩野 浩一, 原山 淳, 前田 良知, 吉田 鉄生, 武田 伸一郎, 宮澤 拓也, 榎戸 輝揚, 田中 孝明, 寺田 幸功, 内山 秀樹, 一戸 悠人, 石橋 和紀, 國枝 秀世, 田村 啓輔, 田原 譲, 三石 郁之, 林 克洋, 林 多佳由, 山岡 和貴, 大野 雅功, 北口 貴雄, 高橋 弘充, 田中 康之, 水野 恒史, 杉田 聡司, 谷津 陽一, 野田 博文, 古澤 彰浩, 山内 茂雄, 中森 健之, 中野 俊男, 牧島 一夫, 内山 泰伸, 斉藤 新也, 片岡 淳, Philippe Laurent, Francois Lebrun, Olivier Limousin, 岡島 崇, 森 英之, 小高 裕和, Madejski G., Blanford R., 他「ひとみ」チーム  

    第17回宇宙科学シンポジウム 講演集 = Proceedings of the 17th Space Science Symposium   2017年1月

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    記述言語:日本語   出版者・発行元:宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)  

    第17回宇宙科学シンポジウム (2017年1月5日-6日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県著者人数: 56名ほか (JAXA staff: Ishida, Manabu ; Kokubun, Motohide ; Watanabe, Shin ; Iizuka, Ryo ; Ohta, Masayuki ; Sato, Rie ; Takahashi, Tadayuki ; Hagino, Koichi ; Harayama, Atsushi ; Maeda, Yoshitomo)資料番号: SA6000060046レポート番号: P-004

  93. 雷雲ガンマ線の多地点観測プロジェクト:可搬型検出器の開発と2016年度冬季の観測成果

    和田有希, 榎戸輝揚, 古田禄大, 湯浅孝行, 中澤知洋, 中野俊男, 土屋晴文, 鴨川仁, 米徳大輔, 澤野達哉  

    日本地球惑星科学連合大会予稿集(Web)2017 巻   頁: ROMBUNNO.MIS18‐05 (WEB ONLY)   2017年

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    記述言語:日本語  

    J-GLOBAL

  94. 雷雲電場による電子加速のガンマ線観測プロジェクト:小型読み出し系の開発と北陸地方における多地点運用

    和田 有希, 牧島 一夫, 鴨川 仁, 瀧田 正人, 米徳 大輔, 澤野 達哉, 渡會 兼也, 米口 一彦, 木村 光一郎, 北野 皓嗣, the GROWTH collaboration, 榎戸 輝揚, 湯浅 孝行, 中澤 知洋, 土屋 晴文, 中野 俊男, 奥田 和史, 古田 禄大, 楳本 大悟  

    日本物理学会講演概要集72 巻 ( 0 ) 頁: 503 - 503   2017年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    <p>雷雲ガンマ線の観測プロジェクトは2015年度より多地点によるマッピング観測を目指し、石川県でも展開を進めている。初年度の運用実績や成果を元にしてADC/FPGAによる読み出し系の改良を中心に開発を行い、小型ガンマ線検出器の台数を増やしつつある。これらの検出器は金沢市内、小松市内、及び柏崎刈羽原発内に設置し、マッピング観測を本格的に開始している。本講演では小型検出器の開発状況、および今年度の運用状況・成果について報告する。</p>

    DOI: 10.11316/jpsgaiyo.72.1.0_503

    J-GLOBAL

  95. 雷雲電場による電子加速のガンマ線観測プロジェクト:多地点体制への新展開

    榎戸 輝揚, 牧島 一夫, 鴨川 仁, 瀧田 正人, 米徳 大輔, 澤野 達哉, 渡會 兼也, 米口 一彦, 木村 光一郎, 北野 皓嗣, the GROWTH collaboration, 和田 有希, 湯浅 孝行, 中澤 知洋, 土屋 晴文, 中野 俊男, 奥田 和史, 古田 禄大, 楳本 大悟  

    日本物理学会講演概要集72 巻 ( 0 ) 頁: 502 - 502   2017年

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    記述言語:日本語   出版者・発行元:一般社団法人 日本物理学会  

    <p>雷雲内の強電場で加速された電子からの制動放射ガンマ線を観測するプロジェクトは、2006年に柏崎で観測を開始して以来10年になり、観測事例も蓄積され、基本的な描像は確立しつつある。しかし、電子の加速領域の大きさや継続時間はこれまでの定点観測では把握が難しかったため、石川県内の複数の学校の屋上に、小型で低消費電力の放射線検出器を設置し、マッピング観測を新たに開始した。多地点観測への新展開プロジェクトの狙いと現状を報告する。</p>

    DOI: 10.11316/jpsgaiyo.72.1.0_502

    J-GLOBAL

  96. 雷雲ガンマ線の多地点観測プロジェクトが拓く新展開

    榎戸輝揚, 和田有希, 古田禄大, 湯浅孝行, 中澤知洋, 中野俊男, 土屋晴文, 鴨川仁, 米徳大輔, 澤野達哉  

    日本地球惑星科学連合大会予稿集(Web)2017 巻   頁: ROMBUNNO.MIS05‐02 (WEB ONLY)   2017年

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    記述言語:日本語  

    J-GLOBAL

▼全件表示

共同研究・競争的資金等の研究課題 2

  1. 雷放電からのガンマ線放射が人々に与えうる被曝量の最大値を求める測定装置の開発

    2021年8月 - 2023年3月

    公益財団法人立松財団  研究助成 

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    担当区分:研究代表者  資金種別:競争的資金

    配分額:3000000円 ( 直接経費:3000000円 )

  2. 相対論的電子を生む自然界唯一の静電場加速器は雷雲のどこにあるのか?

    2020年4月 - 2021年3月

    研究助成 

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    配分額:1000000円

科研費 11

  1. COSI衛星で拓くMeVガンマ線宇宙観測と素粒子物理学

    研究課題/研究課題番号:24H00244  2024年4月 - 2029年3月

    科学研究費助成事業  基盤研究(A)

    高橋 忠幸, 中澤 知洋, 松本 重貴, Melia Thomas

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    担当区分:研究分担者 

    2027年打ち上げ予定のMeV全天観測衛星COSIはGe半導体を用いたコンプトン望遠鏡を主検出器とし、これまでより1桁良い検出感度を持つ。特に、高いエネルギー分解能を生かしたガンマ線輝線の観測能力が高く、MeV宇宙物理学を革新する事が期待されている。バックグランドの正確なモデル化が高感度の観測、特に暗黒物質探査のような天体現象以外の信号を探る上で極めて重要である。本研究ではバックグランドのモニターと突発天体観測を目的とした装置の実現をはかる。並行して、MeVスケールの質量を持つ暗黒物質の間接探査を行うための理論的戦略をたてる。打ち上げ後は、バックグランドのモデル化と天体解析を行う。

  2. 日本海沿岸における冬季雷及び関連高エネルギー放射と高高度放電現象の究明

    研究課題/研究課題番号:24H00269  2024年4月 - 2027年3月

    日本学術振興会  科学研究費助成事業  基盤研究(A)

    王 道洪, 鴨川 仁, 佐藤 陽祐, 山下 幸三, 篠田 太郎, 中澤 知洋, ウ ティン

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    担当区分:研究分担者 

    日本海沿岸の冬季雷はエネルギーの極めて大きいものが多く、大型風車等の施設に大きな被害をもたらす一方、伝統的な理論で理解できない高エネルギー放射線、雷雲上部から電離層に達する高高度放電現象もしばしば観測されている。本研究は冬季雷の3D放電マッピングシステムを高度化した上で、気象偏波レーダー、電界計アレイ、ガンマ線検出器アレイ、高速カメラを集中的に配置して連携観測することで、世界に類を見ない雷放電の全波長観測を実現し、数値シミュレーションと合わせて、冬季雷の高い電磁エネルギーが雷雲の中でどのように蓄積・分布・放電され、どのようにガンマ線や高高度放電現象を発生させているのかを解明する。

  3. ISS搭載の世界初の大気X線観測専用装置で実現する超高層大気の膨張収縮の研究

    研究課題/研究課題番号:23H00151  2023年4月 - 2027年3月

    日本学術振興会  科学研究費助成事業  基盤研究(A)

    信川 久実子, 武田 彩希, 中澤 知洋, 勝田 哲

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    担当区分:研究分担者 

    高度100 km付近の超高層大気は、気候変動を予測する上で重要な研究対象である一方、超高層大気の変動を引き起こすメカニズムは複雑で、未だ全容解明されていない。問題は、人工衛星や気球でその場観測できない高度のため、大気の中で最もデータが乏しいことである。我々は近年、X線天文衛星が偶然地球を向くわずかな観測時間を利用して、宇宙X線の大気減光を用いて超高層大気密度の鉛直分布を測定できることを実証した。本研究は、大気X線観測の専用装置を独自に開発し、国際宇宙ステーションに搭載することで、超高層大気を長時間観測する。太陽と下層大気の影響を定量評価し、超高層大気の変動メカニズムを解明する。

  4. 高エネルギー大気物理学の手法で挑む雷トリガー機構の解明

    研究課題/研究課題番号:22H00145  2022年4月 - 2026年3月

    日本学術振興会  科学研究費助成事業  基盤研究(A)

    榎戸 輝揚, 鴨川 仁, 一方井 祐子, 中澤 知洋, 森本 健志

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    担当区分:研究分担者 

    雷と雷雲は天然の粒子加速器である。雷や雷雲内では、強電場による電子の相対論的加速が生じ、MeV を超える制動放射ガンマ線が発生する。日本海沿岸の冬季雷雲は、これを地上観測できる世界的にも稀な絶好の条件を備える。本研究では、雷雲からの放射線と、雷の原子核反応の研究を組み合わせ、未解明の雷のトリガー過程に大気中の高エネルギー電子がどう関係するかを解明する。そのため、多地点観測網をシチズ ンサイエンスで拡大し、新型の中性子モニタも導入する。これにより、これまでに蓄積した成果 を集大成し「雷雲と雷放電の高エネルギー大気物理学」という新分野の根幹を確立したい。
    雷と雷雲は天然の粒子加速器である。雷の放電路や雷雲内では、強電場による電子の相対論的加速が生じ、MeV を超える制動放射ガンマ線が発生すると考えられている。私達は、このような高エネルギーの電子流が暴走的に発展し、雷のトリガー(Lightning initiation)に発展していくのかという謎に観測的な研究から挑んでいる。このような研究を実施する上で、日本海沿岸の冬季雷雲は、これを地上観測できる世界的にも稀な絶好の条件を備えている。雷放電の直前に、相対論的な電子の雪崩増幅が発生しているのかを検証するため、私たちは金沢の周辺に観測ネットワークを構築し、雷雲から地上に降り注ぐガンマ線のバースト現象を監視できる体制を整えるのが本研究の骨格である。
    2022年度は、これまでに開発を進めてきた可搬型の放射線モニタ「コガモ」(Compact Gamma-ray Monitor)を76台、金沢の周辺に設置して、多地点の観測網を構築できた。これらのコガモは、郵送により市民サポーターのご自宅に配達し設置していただき観測を実施するシチズンサイエンスの枠組みで運用できた。取得したデータの一部はオンラインでサーバーに配信し、研究者や参加している市民サポーターがウェブサイトで視覚的に確認できる体制を整えた。また、これまでの観測データの中で、2021年12月30日に記録された現象の解析を進め、論文として投稿した。
    さらに、シチズンサイエンスの枠組みを推進するため、金沢市内で「シチズンサイエンス・ワークショップ:雷から文化を創造する」を開催した。また、理研・和光キャンパスの一般公開、TEDxTokyo 2022で紹介するとともに、NHK コズミックフロント「雷-知られざる全貌に迫る-」でも我々のプロジェクトが紹介された。
    シチズンサイエンスを活用した物理学的研究という新しい枠組みに挑戦し、放射線の多地点ネットワークを構築して実際に科学研究を実施できている点を自負している。特に、2021年12月30日に金沢市内の複数のコガモで記録されていた雷雲からのガンマ線バースト事象を詳しく解析したところ、ガンマ線の瞬間途絶と同期して雷放電が発生しており、その雷放電の開始位置を電波観測のデータから推測すると、ガンマ線照射領域の上空で発生していることがわかった。これは、ガンマ線を出すような相対論的な電子が雷放電のトリガーに関わっている可能性を示す観測的な示唆として、解析を進め、学術誌に投稿している。このようにシチズンサイエンスでの多地点観測での科学成果が順調に得られつつある。さらに、シチズンサイエンスのような複数のプレーヤーが関わるプロジェクトの円滑な遂行に向けて、市民サポーターを交えたワークショップも開催することができた。
    ガンマ線に感度のあるコガモ観測ネットワークは構築できつつあるため、次は中性子を測定する検出器の基礎開発を進め、金沢の市街地に複数点の設置を行いたい。中性子は、強烈なガンマ線が大気中で原子核反応(光核反応)を起こすときに発生させるものであり、雷のトリガーに関わる重要な情報になると期待できる。
    コガモを用いた観測ネットワークは本年度も維持する。コガモは夏季期間中は高温多湿でシンチレータが劣化するのを避けるため、大学・研究所に保管しメンテナンスを行い、冬季に再度の設置を実施する。
    シチズンサイエンスとしてアウトリーチの必要性も重視しており、2023年度は七尾高校等での出前授業やワークショップを企画する。

  5. 高速半導体イメージャによる雷からのMeVガンマ線フラッシュの精密探査

    研究課題/研究課題番号:21H00166  2021年4月 - 2023年3月

    日本学術振興会  科学研究費助成事業  新学術領域研究(研究領域提案型)

    中澤 知洋

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    担当区分:研究代表者 

    配分額:6630000円 ( 直接経費:5100000円 、 間接経費:1530000円 )

    雷放電に伴って観測される突発MeVガンマ線は高い光度を持ち、電子が大規模に静電場加速を受けている直接証拠であるが、加速メカニズムはまだ理解されていない。今大事なことは、加速現場の位置を知り、観測の環境を同定することである。しかし極限の高輝度環境の中で~10 MeVガンマ線の入射方向を検知できる装置は既存では存在しない。TimePix3 高速半導体イメージャは、~50 umの精度での3次元トラック能力を有しており、10~MeVガンマ線による電子陽電子対生成をトラックして入射方向を検出できる。その検出方法を確立し、現在北陸に展開中の雷ガンマ線観測装置の小屋にこれを追加して、実観測に臨む。
    雷活動に伴って観測されるMeVガンマ線は、自然界で唯一知られている電子が大規模に静電場加速を受けている直接証拠である。雷ガンマ線フラッシュ現象では、30 MeVに達するガンマ線が1uGyを超える大強度で 100 usの短時間に地上に照射される。最新理論では、加速器から100 m 以内では最大1Gyにも達する極めて大強度となる可能性が指摘されており、「どこでどれだけの電子加速が起きている か」を知ることは学術的価値だけでなく、防雷や被曝の観点からも重要である。 本研究では雷ガンマ線フラッシュを撮像してその空間位置を知る新技術の開発を目指している。既存のガンマ線検出器では、大強度の信号は飽和するし、指向性を得られない。そこでピクセル型半導体イメージャtimepix3を用いた電子飛跡計測によって、ガンマ線が産むコンプトン反跳電子や対生成電子の指向性をえてガンマ線の指向性を計測する新しいアプローチを開発した。2021年度は中性子施設KUANSで0.1-8 MeVで雷ガンマ線スペクトルに似せたガンマ線を得られることを確認しtimepix3でガンマ線入射方向を計測できることを原理検証した。2022年度 には、冬季の金沢に設置するための2台目のtimepix検出器を購入し、KUANSでのMeVガンマ線照射試験を色々な方向から実施し、角分解能10度程度という要求を満たすことを確認した、2022年12月から金沢での長期計測を開始し、翌3月まで連続運転に成功した。この中で1回の雷ガンマ線フラッシュの計測にも成功した。このイベントは明るすぎ、timepixの断面積が小さいにもかかわらず、データが飽和してしまっていたが、飛跡を複数捕え、原理的に指向性を得られることを検証でき、この成果は2023年度のJpGU2023年会で発表予定である。今後も設置を継続する予定である
    令和4年度が最終年度であるため、記入しない。
    令和4年度が最終年度であるため、記入しない。

  6. 半導体コンプトンカメラによるMeV宇宙観測の開拓

    研究課題/研究課題番号:20H00157  2020年4月 - 2024年3月

    日本学術振興会  科学研究費助成事業  基盤研究(A)

    中澤 知洋, 武田 伸一郎

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    担当区分:研究代表者 

    配分額:44850000円 ( 直接経費:34500000円 、 間接経費:10350000円 )

    最初の2年間は、地上においてSi/CdTe-SCTとシールドを組み合わせた試作検出器を開発し、地上試験を中心にその性能評価を進める。気球搭載のためには、コンパクトかつ低消費電力であることが重要である。研究計画の後半の2年間では、この検出器を改良して大気球用のゴンドラに搭載し、海外の長時間気球への搭載を調整するのと並行して、国内での調整も進め、短時間で良いので高度35-50 km の大気球高度にあげて、その高度でのバックグラウンドなどの観測性能を実証する。このため、2年目ごろから気球実験の視察や、海外コラボレータとの連携による超長時間気球へのチャレンジも進める。
    宇宙観測でMeVガンマ線だけは観測感度が数桁も劣り、その改善は宇宙観測の最重要課題の一つである。有力な解として世界中で半導体コンプトン望遠鏡 (Semiconductor Compton Telescope, SCT)の開発が進んでいる。我々は広島大学やJAXA等とともに日本独自のSi/CdTe-SCTを開発 し、2016年に「ひとみ」衛星に搭載してSCTとして世界で唯一軌道上で動作実績を得た。初期運用中に衛星が失われてしまったが、たった1.5 時間の観測で「かに星雲」の100 keV帯の偏光観測に成功するなど、開発の最先端にある。本研究では「アクティブシールド付きSi/CdTe-SCT」の、将来の超長時間気球への適用を目指し、小型の試作機miniSGDを用いてその観測性能を検証する試験観測を実施することを目標とする。装置の基本構成部分に、次世代の硬X線の高感度観測を目指すFORCE衛星向けに開発中の技術を採用し、その基礎開発も兼ねている。
    2023年初頭の気球実験へ向けて、2021年度は急ピッチで検出器システムを開発した。コアとなる SCT は、CdTe部を9月までに4セット、シリコン部も11月までに2セット揃え、データ取得系も含めてSCTとしての動作試験を12月に実施した。コンプトン撮像に成功し、正しく動作していることを示した。シールド部の開発も進め、12月には全系を組み合わせた動作試験を実施した。その後、試験場所を名大に移動して試験を継続し性能検証を進めている。電源となる電池の手配も終わり、耐圧容器の鍵を握る入射窓の開発と耐圧試験を実施した。データ送信やコマンド受信系の開発も進めた。
    また提案に参加しているアメリカのMeV観測小型衛星COSIが、12月に2025年打ち上げで採択され、米欧日のコラボレーションが立ち上がった。MeV宇宙観測の新時代がまさに始まりつつある。
    2023年4-5月のフライトに向けて、全系の開発を進めた。主要コンポーネントとして、SCTとBGOアクティブシールドは、全検出器ユニット、全読み出し系、検出器内配線、そして支持構造を含めて、足並みが揃って組み上げ・総合動作検証にまで到達した。低温試験も実施して、ヒーターの配置と動作試験も実施している。また、構造周りでは鍵を握る入射窓の低温耐圧試験を繰り返して技術を確立し、構造設計を進めてゴンドラ設計との調整も進めた。耐圧容器の設計もほぼ終わり、耐圧容器の主要部も納品され、現在、フィットチェック中である。国際・社会情勢による輸出入の混乱に備えて電池も予備を含めて全数購入した。システム全体の動作試験を進め、SCTとしてのファーストライトを得ており、耐圧容器やゴンドラとのインタフェースなども、遅れつつも予定のマージン内で開発が進んでいる。これらの成果は、物理学会や名古屋大学の学位論文としてまとめられており、後者は発表会で高い評価を得た。
    昨年12月のCOSI衛星の採択は、MeV天文学全体にとって非常に重要な一歩であり、その日本チームメンバーとしての活動として、サイエンス検討の参加、サブ検出器の開発支援などが具体的に立ち上がった。20年ぶりに再開するMeV全天観測において、日本のプレゼンスをしっかり示すことができるよう、共同研究を加速させている。
    2022年度の末には、オーストラリアの射場に我々も展開する予定であり、今後は急ピッチで装置を完成させる。合わせて、その性能を強化するパラメータ調整を進め、オーストラリア移動前に検出器性能を確立させる。また、2022年7月には2年に一度の国際学会にでminiSGD実験のコンセプトの発表をする予定である。今後は、性能評価試験の継続、さらに検討している改善項目の実現のための改造、耐圧試験・低温試験などの環境試験の実施、ゴンドラとの噛み合わせなど、気球実験実現のための研究開発を着実に進めてゆく。2023年2月には現地に装置を発送し、4-5月の飛揚を迎える。5月には回収して帰国し、回収時の損傷などをチェックしたのち、第2段階として、FORCE衛星を目指した光電吸収モードでの低バックグラウンド硬X線観測の性能評価へ進みたいと希望している。
    MeV観測小型衛星COSIの2025年打ち上げがNASAで採択されたことは、MeV天文学の進展に大きなプラスとなった。COSIはGe半導体に基づく半導体コンプトン望遠鏡であり、銀河系内の核ガンマ線放射を桁違いの高い感度・精度で観測できるようになる。検出器が重元素ベースであるために、量子論的なドップラーブロードニング効果により角分解能もminiSGDほどは高くないが、全天の突発天体監視や偏光観測の能力は高い。このようにCOSIは、「核ガンマ線の宇宙観測」の革新に特徴をもちつつ、小型ながら汎用の全天MeV天文台としての25年ぶりの観測を実現するもので、新しいMeV天文学の時代の先駆けとなる。miniSGDはCOSIと異なり、100-200 keVでの感度と偏光観測能力を重視した設計であり、将来的に相補的な観測を期待している。

  7. 雷ガンマ線フラッシュを航空機から捉える高時間分解能でのガンマ線撮像への挑戦

    研究課題/研究課題番号:19K21899  2019年6月 - 2021年3月

    日本学術振興会  科学研究費助成事業  挑戦的研究(萌芽)

    中澤 知洋

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    担当区分:研究代表者 

    配分額:6370000円 ( 直接経費:4900000円 、 間接経費:1470000円 )

    雷雲や雷放電から到来する20 MeVに達するガンマ線は、雷雲中に天然の静電場粒子加速器という、自然界で他には見られない現象がある証拠である。宇宙から観測される地球由来の突発ガンマ線が、もし雷雲中の数百mのコンパクトな加速域から放射されていると、そこでの放射線量は非常に大きくなる。科学的な興味だけでなく、航空機への被曝なども無視し得ない可能性もある。しかしあまりに大強度なため、観測装置が飽和しない独特の工夫が必要である。本研究では、地上での雷ガンマ線観測の実績に基づき、あらたにチェレンコフ光検出技術も融合し、ガンマ線を一つ一つ捉え、その到来方向も知る軽量小型の装置を開発する。
    雷放電と同期する突発MeVガンマ線 Terrestrial Gamma-ray Flash (TGF)は人工衛星から観測できるほど強力で、発生源の雷雲中の電子加速域の近くを航空機が飛行すると被曝量が大きい可能性があり、その観測的な理解が重要である。非常に高輝度の観測を実現するため、シンチレータ検出器ではなく、チェレンコフ光を用いる新発想の雷ガンマ線検出器の実証機を開発した。アクリル棒の両端をMPPCで計測することでガンマ線の入射方向も知ることができる。コロナのため10 MeVガンマ線源での実験ができなかったが、宇宙線を用いて指向性を検証し、コンパクト、軽量、低消費電力な装置の試作に成功した。
    TGFの被曝量は数値上は人間に影響がないとは言えないほど強い可能性が高い。特に冬季の日本海岸では雷雲の到達高度が低く、その直上を航空機が飛行する際の被曝量の見積もりは重要である。本研究では、TeVガンマ線計測で用いられるチェレンコフ検出の原理を用いて、軽量で指向性を持ち、検出効率を下げることで高輝度のTGFで回路系が飽和しない装置を実現すべく、試作機でその概念を実証した。宇宙観測の技術を生かし、コンパクトで低消費電力なシステムとなっており、航空機への複数このシステムの搭載も容易である。今後はTGFの地上観測でも利用しつつ、より大型の予算により航空機搭載型の本格装置の開発を目指す。

  8. 雷や雷雲中の電子加速に由来する光核反応の検証

    研究課題/研究課題番号:18H01236  2018年4月 - 2021年3月

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    土屋 晴文, 鳥居 建男, 中澤 知洋

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    担当区分:研究分担者 

    雷や雷雲が医療の現場にあるX線発生装置と同様な仕組み(制動放射)でX線を発生させる。加えて、近年では雷で発生した高エネルギー制動放射線が原子核とぶつかり、中性子をはじき出す光核反応を起こすことも明らかになった。本研究では光核反応を引き起こすガンマ線閃光の詳細を調べた。その結果、約100京個の高エネルギー電子がガンマ線閃光の発生に寄与し、光核反応で発生した中性子は発生点から1 kmにわたり広がり、その減衰時間が50ミリ秒ほどと推定された。
    雷の発生にあわせてガンマ線閃光が発生する。それゆえ、ガンマ線閃光の発生メカニズムを理解することは雷の発生メカニズムの解明にもつながると考えられている。本研究により、その発生に約100京個の電子が寄与していることが分かり、今後の雷の発生モデルの構築に資すると期待される。また、多くのガンマ線閃光が光核反応を起こすことも明らかになった。雷による光核反応の詳細を理解することは、炭素14年代測定や初期地球大気における元素生成などの研究にも影響を与える可能性もある。

  9. マグネターの 自由歳差運動の観測と内部磁場の推定

    研究課題/研究課題番号:15H03653  2015年4月 - 2018年3月

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    牧島 一夫, 中澤 知洋

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    担当区分:研究分担者 

    我々は2つのマグネターで硬X線パルスが、パルス周期の1万倍程度の長周期で位相変調を受けていることを発見した。これは内部の強いトロイダル磁場により、これら中性子星が僅か変形して自由歳差運動が起き、それと自転周期とのうなりが現れたと解釈された。本研究では米国NuSTAR衛星のデータを用い、これら2天体で現象が再確認されたが、変調振幅は「すざく」の値と大幅に変化していた。「すざく」で観測された別のマグネターからは、周期 48 ksで硬X線パルスの位相変調が検出された。MAXIを用いX線パルサーの光度とパルス周期変化率の相関を調べた結果、X Perseiはマグネター並の超強磁場を持つことが判明した。

  10. 銀河団衝突の初期に解放される莫大な重力エネルギーの行方の観測

    研究課題/研究課題番号:15H03639  2015年4月 - 2018年3月

    日本学術振興会  科学研究費助成事業  基盤研究(B)

    中澤 知洋, 赤堀 卓也, 滝沢 元和, 加藤 祐一

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    担当区分:研究代表者 

    配分額:16380000円 ( 直接経費:12600000円 、 間接経費:3780000円 )

    宇宙最大の天体、銀河団が衝突・合体する時に解放される莫大なエネルギーが、高温ガスの加熱、乱流の励起、さらに粒子加速や磁場増幅にどのように使われるかを知るために2つの研究を行なった。衝突銀河団CIZA J1358,9-4750を複数のX線天文衛星と電波天文台で観測し、衝突の初期段階にあること、それにも関わらず複雑な構造を持つことを確認した。並行して超精密分光によるドップラー観測と、高感度硬X線観測による加熱の観測精度向上を目指し、ASRTO-H衛星での観測を目指した。観測はできなかったものの、軌道上でASTRO-Hの硬X線観が世界最高感度にあることを実証し、将来検出器への指針を得た。
    宇宙最大の天体が合体する「銀河団衝突」の中では、莫大なエネルギーが解放され、加熱、乱流、粒子加速などが起きる。しかし、そのエネルギーがどこへ行くかは解明されていない。既存のX線衛星、電波観測で研究を続けつつ、最新のX線衛星ASTRO-Hで、運動エネルギーや加熱をかつてない精度で観測することを目指した。2016年2月に打ち上げられ、担当していた硬X線検出器も世界最高の感度を達成したが、衛星喪失による本格観測には至らなかった。しかし、これまで難しいとされてきた硬X線での高感度観測のレシピを確立し実証できたことで、将来計画をより高性能にできる。

  11. 次世代多波長観測と理論シミュレーションの連携で解明する銀河団の非熱的現象

    研究課題/研究課題番号:26400218  2014年4月 - 2018年3月

    日本学術振興会  科学研究費助成事業  基盤研究(C)

    滝沢 元和, 中澤 知洋, 北山 哲

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    担当区分:連携研究者 

    X線と電波観測により銀河団電波レリックでの粒子加速過程とその物理状態を解明し、理論モデルの構築を行った。特にtoothbrush電波レリックでの粒子加速過程が単純な衝撃波統計加速では説明のつかないことを明らかにした。ALMAを用いて5秒角というこれまでにない空間分解能のSZ効果観測をおこない、RX J1347.5-1145銀河団の超高温成分がX線ピークと異なる場所にあることを明確に示した。低周波電波での宇宙磁場研究についてPASJ誌の招待レビュー論文に対して、銀河団のパートなどに分担執筆者として貢献をした。

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