Updated on 2022/04/12

写真a

 
KOBAYASHI Hiroshi
 
Organization
Graduate School of Science Assistant Professor
Graduate School
Graduate School of Science
Undergraduate School
School of Science Department of Physics
Title
Assistant Professor

Degree 1

  1. Ph. D. ( 2004.3   Tokyo Institute of Technology ) 

Research Areas 3

  1. Natural Science / Astronomy  / Astronomy

  2. Natural Science / Space and planetary sciences  / Planetary Science

  3. Natural Science / Space and planetary sciences

 

Papers 73

  1. Rapid Formation of Gas-giant Planets via Collisional Coagulation from Dust Grains to Planetary Cores Reviewed

    Kobayashi, Hiroshi; Tanaka, Hidekazu

    ASTROPHYSICAL JOURNAL   Vol. 922   page: id. 16   2021.11

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    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: doi.org/10.3847/1538-4357/ac289c

  2. Coagulation Instability in Protoplanetary Disks: A Novel Mechanism Connecting Collisional Growth and Hydrodynamical Clumping of Dust Particles Reviewed

    Tominaga, Ryosuke, T.; Inutsuka, Shu-ichiro, Kobayashi, Hiroshi

    ASTROPHYSICAL JOURNAL   Vol. 923   page: id.34   2021.12

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    Authorship:Last author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: doi.org/10.3847/1538-4357/ac173a

  3. Effect of Dust Size on the Near-infrared Spectra (1.0-5.0 μm) of Brown Dwarf Atmospheres Reviewed

    Sorahana, Satoko; Kobayashi, Hiroshi ; Tanaka, Kyoko K.

    ASTROPHYSICAL JOURNAL   Vol. 919   page: id. 117   2021.10

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: doi.org/10.3847/1538-4357/ac1271

  4. SPH simulations for shape deformation of rubble-pile asteroids through spinup: The challenge for making top-shaped asteroids Ryugu and Bennu Reviewed

    Sugiura, Keisuke; Kobayashi, Hiroshi ; Watanabe, Sei-ichiro search by orcid ; Genda, Hidenori search by orcid ; Hyodo, Ryuki ; Inutsuka, Shu-ichiro

    Icarus     2021.9

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: doi.org/10.1016/j.icarus.2021.114505

  5. The Growth of Protoplanets via the Accretion of Small Bodies in Disks Perturbed by the Planetary Gravity Reviewed

    Okamura, Tatsuya; Kobayashi, Hiroshi

    ASTROPHYSICAL JOURNAL   Vol. 916   page: id. 109   2021.8

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    Authorship:Last author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: doi.org/10.3847/1538-4357/ac06c6

  6. A systematic study of silicate absorption features in heavily obscured AGNs observed by Spitzer/IRS Reviewed

    Tsuchikawa, T. ; Kaneda, H. ; Oyabu, S. ; Kokusho, T. ; Kobayashi, H. ; Yamagishi, M. ; Toba, Y.

    ASTRONOMY & ASTROPHYSICS   Vol. 651   page: A117   2021.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: doi.org/10.1051/0004-6361/202140483

  7. Photoevaporation of Grain-depleted Protoplanetary Disks around Intermediate-mass Stars: Investigating the Possibility of Gas-rich Debris Disks as Protoplanetary Remnants Reviewed International coauthorship

    Nakatani, Riouhei; Kobayashi, Hiroshi; Kuiper, Rolf; Nomura, Hideko; Aikawa, Yuri

    ASTROPHYSICAL JOURNAL   Vol. 915   page: id. 90   2021.7

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    DOI: doi.org/10.3847/1538-4357/ac0137

  8. Collisional Growth and Fragmentation of Dust Aggregates with Low Mass Ratios. I. Critical Collision Velocity for Water Ice Reviewed

    Hasegawa, Yukihiko; Suzuki, Takeru K.; Tanaka, Hidekazu; Kobayashi, Hiroshi; Wada, Koji

    ASTROPHYSICAL JOURNAL   Vol. 915   page: id.22   2021.7

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    DOI: doi.org/10.3847/1538-4357/abf6cf

  9. New Growth Mechanism of Dust Grains in Protoplanetary Disks with Magnetically Driven Disk Winds Reviewed

    Taki Tetsuo, Kuwabara Koh, Kobayashi Hiroshi, Suzuki Takeru K.

    ASTROPHYSICAL JOURNAL   Vol. 909 ( 1 )   2021.3

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    DOI: 10.3847/1538-4357/abd79f

    Web of Science

  10. Ring Formation by Coagulation of Dust Aggregates in the Early Phase of Disk Evolution around a Protostar Reviewed International coauthorship

    Ohashi Satoshi, Kobayashi Hiroshi, Nakatani Riouhei, Okuzumi Satoshi, Tanaka Hidekazu, Murakawa Koji, Zhang Yichen, Liu Hauyu Baobab, Sakai Nami

    ASTROPHYSICAL JOURNAL   Vol. 907 ( 2 )   2021.2

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    DOI: 10.3847/1538-4357/abd0fa

    Web of Science

  11. Is water ice an efficient facilitator for dust coagulation? Reviewed

    Kimura Hiroshi, Wada Koji, Kobayashi Hiroshi, Senshu Hiroki, Hirai Takayuki, Yoshida Fumi, Kobayashi Masanori, Hong Peng K., Arai Tomoko, Ishibashi Ko, Yamada Manabu

    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY   Vol. 498 ( 2 ) page: 1801 - 1813   2020.10

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1093/mnras/staa2467

    Web of Science

  12. Sample collection from asteroid (162173) Ryugu by Hayabusa2: Implications for surface evolution Reviewed

    Morota T., Sugita S., Cho Y., Kanamaru M., Tatsumi E., Sakatanit N., Honda R., Hirata N., Kikuchi H., Yamada M., Yokota Y., Kamedal S., Matsuoka M., Sawada H., Honda C., Kouyama T., Ogawa K., Suzuki H., Yoshioka K., Hayakawa M., Hirata N., Hirabayashi M., Miyamoto H., Michikami T., Hiroi T., Hemmi R., Barnouin O. S., Ernst C. M., Kitazatou K., Nakamura T., Riu L., Senshu H., Kobayashi H., Sasaki S., Komatsu G., Tanabe N., Fujii Y., Irie T., Suemitsu M., Takaki N., Sugimoto C., Yumoto K., Ishida M., Kato H., Moroi K., Domingue D., Michel P., Pilorget C., Iwata T., Abe M., Ohtake M., Nakauchi Y., Tsumura K., Yabuta H., Ishihara Y., Noguchi R., Matsumoto K., Miura A., Namiki N., Tachibana S., Arakawa M., Ikeda H., Wada K., Mizuno T., Hirose C., Hosoda S., Mori O., Shimada T., Soldini S., Tsukizaki R., Yano H., Ozaki M., Takeuchi H., Yamamoto Y., Okada T., Shimaki Y., Shirai K., Iijima Y., Noda H., Kikuchi S., Yamaguchi T., Ogawa N., Ono G., Mimasu Y., Yoshikawa K., Takahashi T., Takei Y., Fujii A., Nakazawa S., Terui F., Tanaka S., Yoshikawa M., Saiki T., Watanabe S., Tsuda Y.

    SCIENCE   Vol. 368 ( 6491 ) page: 654 - +   2020.5

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1126/science.aaz6306

    Web of Science

  13. High-resolution simulations of catastrophic disruptions: Resultant shape distributions

    Sugiura Keisuke, Kobayashi Hiroshi, Inutsuka Shu-ichiro

    PLANETARY AND SPACE SCIENCE   Vol. 181   2020.2

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.pss.2019.104807

    Web of Science

  14. Importance of Giant Impact Ejecta for Orbits of Planets Formed during the Giant Impact Era

    Kobayashi Hiroshi, Isoya Kazuhide, Sato Yutaro

    ASTROPHYSICAL JOURNAL   Vol. 887 ( 2 )   2019.12

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    DOI: 10.3847/1538-4357/ab5307

    Web of Science

  15. First Subarcsecond Submillimeter-wave [CI] Image of 49 Ceti with ALMA

    Higuchi Aya E, Saigo Kazuya, Kobayashi Hiroshi, Iwasaki Kazunari, Momose Munetake, Soon Kang Lou, Sakai Nami, Kunitomo Masanobu, Ishihara Daisuke, Yamamoto Satoshi

    ASTROPHYSICAL JOURNAL   Vol. 883 ( 2 )   2019.10

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.3847/1538-4357/ab3d26

    Web of Science

  16. Collisional elongation: Possible origin of extremely elongated shape of 1I/'Oumuamua

    Sugiura Keisuke, Kobayashi Hiroshi, Inutsuka Shu-ichiro

    ICARUS   Vol. 328   page: 14 - 22   2019.8

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.icarus.2019.03.014

    Web of Science

  17. Near- to mid-infrared spectroscopy of the heavily obscured AGN LEDA 1712304 with AKARI/IRC

    Tsuchikawa T., Kaneda H., Oyabu S., Kokusho T., Morihana K., Kobayashi H., Yamagishi M., Toba Y.

    ASTRONOMY & ASTROPHYSICS   Vol. 626   2019.6

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    DOI: 10.1051/0004-6361/201935483

    Web of Science

  18. Toward understanding the origin of asteroid geometries Variety in shapes produced by equal-mass impacts

    Sugiura K, Kobayashi H, Inutsuka S

    ASTRONOMY & ASTROPHYSICS   Vol. 620   2018.12

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1051/0004-6361/201833227

    Web of Science

  19. Collisional Disruption of Planetesimals in the Gravity Regime with iSALE Code: Comparison with SPH code for Purely Hydrodynamic Bodies Reviewed

    Ryo Suetsugu, Hidekazu Tanaka, Hiroshi Kobayashi, Hidenori Genda

    Icarus   Vol. 314   page: 121-132   2018.11

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    DOI: 10.1016/j.icarus.2018.05.027

  20. From Planetesimal to Planet in Turbulent Disks. II. Formation of Gas Giant Planets

    Kobayashi Hiroshi, Tanaka Hidekazu

    ASTROPHYSICAL JOURNAL   Vol. 862 ( 2 )   2018.8

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.3847/1538-4357/aacdf5

    Web of Science

  21. Star formation induced by cloud-cloud collisions and galactic giant molecular cloud evolution Reviewed

    Kobayashi Masato I. N., Kobayashi Hiroshi, Inutsuka Shu-ichiro, Fukui Yasuo

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN   Vol. 70   2018.5

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    DOI: 10.1093/pasj/psy018

    Web of Science

  22. Impact erosion model for gravity-dominated planetesimals Reviewed

    H. Genda, T. Fujita, H. Kobayashi, H. Tanaka, R. Suetsugu, Y. Abe

    Icarus   Vol. 294   page: 234-246   2017.9

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  23. Impact erosion model for gravity-dominated planetesimals

    Genda Hidenori, Fujita Tomoaki, Kobayashi Hiroshi, Tanaka Hidekazu, Suetsugu Ryo, Abe Yutaka

    ICARUS   Vol. 294   page: 234-246   2017.9

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    DOI: 10.1016/j.icarus.2017.03.009

    Web of Science

  24. A likely detection of a local interplanetary dust cloud passing near the Earth in the AKARI mid-infrared all-sky map

    D. Ishihara, T. Kondo, H. Kaneda, T. Suzuki, K. Nakamichi, S. Takaba, H. Kobayashi, S. Masuda, T. Ootsubo, J. Pyo, T. Onaka

    ASTRONOMY & ASTROPHYSICS   Vol. 603   2017.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:EDP SCIENCES S A  

    Context. We are creating the AKARI mid-infrared all-sky diffuse maps. Through a foreground removal of the zodiacal emission, we serendipitously detected a bright residual component whose angular size is about 50 degrees x 20 degrees at a wavelength of 9 mu m.
    Aims. We investigate the origin and the physical properties of the residual component.
    Methods. We measured the surface brightness of the residual component in the AKARI mid-infrared all-sky maps.
    Results. The residual component was significantly detected only in 2007 January, even though the same region was observed in 2006 July and 2007 July, which shows that it is not due to the Galactic emission. We suggest that this may be a small cloud passing near the Earth. By comparing the observed intensity ratio of I-9 mu m/I-18 mu m with the expected intensity ratio assuming thermal equilibrium of dust grains at 1 AU for various dust compositions and sizes, we find that dust grains in the moving cloud are likely to be much smaller than typical grains that produce the bulk of the zodiacal light.
    Conclusions. Considering the observed date and position, it is likely that it originates in the solar coronal mass ejection ( CME) which took place on 2007 January 25.

    DOI: 10.1051/0004-6361/201628954

    Web of Science

  25. Size dependence of dust distribution around the earth orbit Reviewed

    T. Ueda, H. Kobayashi, T. Takeuchi, D. Ishihara, T. Kondo, H. Kaneda

    Astrophysical Journal   Vol. 153 ( 5 ) page: 232   2017.5

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  26. Faint warm debris disks around nearby bright stars explored by AKARI and IRSF Reviewed

    Daisuke Ishihara, Nami Takeuchi, Hiroshi Kobayashi, Takahiro Nagayama, Hidehiro Kaneda, Shu-ichiro Inutsuka, Hideaki Fujiwara, Takashi Onaka

    Astronomy & Astrophysics   Vol. 601   page: A72   2017.5

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  27. Faint warm debris disks around nearby bright stars explored by AKARI and IRSF

    Daisuke Ishihara, Nami Takeuchi, Hiroshi Kobayashi, Takahiro Nagayama, Hidehiro Kaneda, Shu-ichiro Inutsuka, Hideaki Fujiwara, Takashi Onaka

    ASTRONOMY & ASTROPHYSICS   Vol. 601   page: A72   2017.5

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    Context. Debris disks are important observational clues for understanding planetary-system formation process. In particular, faint warm debris disks may be related to late planet formation near 1 au. A systematic search of faint warm debris disks is necessary to reveal terrestrial planet formation.
    Aims. Faint warm debris disks show excess emission that peaks at mid-IR wavelengths. Thus we explore debris disks using the AKARI mid-IR all-sky point source catalog (PSC), a product of the second generation unbiased IR all-sky survey.
    Methods. We investigate IR excess emission for 678 isolated main-sequence stars for which there are 18 mu m detections in the AKARI mid-IR all-sky catalog by comparing their fluxes with the predicted fluxes of the photospheres based on optical to near-IR fluxes and model spectra. The near-IR fluxes are first taken from the 2MASS PSC. However, 286 stars with Ks < 4.5 in our sample have large flux errors in the 2MASS photometry due to saturation. Thus we have measured accurate J, H, and Ks band fluxes, applying neutral density (ND) filters for Simultaneous InfraRed Imager for Unbiased Survey (SIRIUS) on IRSF, the phi 1.4m near-IR telescope in South Africa, and improved the flux accuracy from 14% to 1.8% on average.
    Results. We identified 53 debris-disk candidates including eight new detections from our sample of 678 main-sequence stars. The detection rate of debris disks for this work is similar to 8%, which is comparable with those in previous works by Spitzer and Herschel.
    Conclusions. The importance of this study is the detection of faint warm debris disks around nearby field stars. At least nine objects have a large amount of dust for their ages, which cannot be explained by the conventional steady-state collisional cascade model.

    DOI: 10.1051/0004-6361/201526215

    Web of Science

  28. Size Dependence of Dust Distribution around the Earth Orbit

    Ueda Takahiro, Kobayashi Hiroshi, Takeuchi Taku, Ishihara Daisuke, Kondo Toru, Kaneda Hidehiro

    ASTRONOMICAL JOURNAL   Vol. 153 ( 5 )   2017.5

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    DOI: 10.3847/1538-3881/aa5ff3

    Web of Science

  29. Detection of Submillimeter-wave [C i] Emission in Gaseous Debris Disks of 49 Ceti and β Pictoris Reviewed

    Aya E Higuchi, Aki Sato, Takashi Tsukagoshi, Nami Sakai, Kazunari Iwasaki, Munetake Momose, Hiroshi Kobayashi, Daisuke Ishihara, Sakae Watanabe, Hidehiro Kaneda, Satoshi Yamamoto

    Astrophysical Journal   Vol. 839 ( 1 ) page: L14   2017.4

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  30. Orbital Evolution of Moons in Weakly Accreting Circumplanetary Disks

    Yuri I Fujii, Hiroshi Kobayashi, Sanemichi Z Takahashi, Oliver Gressel

    Astronomical Journal   Vol. 153 ( 4 ) page: 194   2017.4

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  31. Detection of Submillimeter-wave [CI] Emission in Gaseous Debris Disks of 49 Ceti and beta Pictoris

    Aya E. Higuchi, Aki Sato, Takashi Tsukagoshi, Nami Sakai, Kazunari Iwasaki, Munetake Momose, Hiroshi Kobayashi, Daisuke Ishihara, Sakae Watanabe, Hidehiro Kaneda, Satoshi Yamamoto

    ASTROPHYSICAL JOURNAL LETTERS   Vol. 839 ( 1 ) page: L14   2017.4

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    We have detected [C I] P-3(1)-P-3(0) emissions in the gaseous debris disks of 49 Ceti and beta Pictoris with the 10 m telescope of the Atacama Submillimeter Telescope Experiment, which is the first detection of such emissions. The line profiles of [C I] are found to resemble those of CO(J = 3-2) observed with the same telescope and the Atacama Large Millimeter/submillimeter Array. This result suggests that atomic carbon (C) coexists with CO in the debris disks. and is likely formed by the photodissociation of CO. Assuming an optically thin [C I] emission with the excitation temperature ranging from 30 to 100. K, the column density of C is evaluated to be (2.2 +/- 0.2). x. 10(17) and (2.5 +/- 0.7). x. 10(16). cm(-2) for 49 Ceti and beta Pictoris, respectively. The C/CO column density ratio is thus derived to be 54 +/- 19 and 69 +/- 42 for 49 Ceti and beta Pictoris, respectively. These ratios are higher than those of molecular clouds and diffuse clouds by an order of magnitude. The unusually high ratios of C to CO are likely attributed to a lack of H-2 molecules needed to reproduce CO molecules efficiently from C. This result implies a small number of H-2 molecules in the gas disk,. i.e., there is an appreciable contribution of secondary gas from dust grains.

    DOI: 10.3847/2041-8213/aa67f4

    Web of Science

  32. Orbital Evolution of Moons in Weakly Accreting Circumplanetary Disks

    Fujii Yuri I., Kobayashi Hiroshi, Takahashi Sanemichi Z., Gressel Oliver

    ASTRONOMICAL JOURNAL   Vol. 153 ( 4 )   2017.4

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    DOI: 10.3847/1538-3881/aa647d

    Web of Science

  33. Evolutionary Description of Giant Molecular Cloud Mass Functions on Galactic Disks Reviewed

    Masato I.N. Kobayashi, Shu-ichiro Inutsuka, Hiroshi Kobayashi, Kenji Hasegawa

    Astrophysical Journal   Vol. 836 ( 2 ) page: 175   2017.2

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    DOI: 10.3847/1538-4357/836/2/

  34. Evolutionary Description of Giant Molecular Cloud Mass Functions on Galactic Disks

    Masato I. N. Kobayashi, Shu-ichiro Inutsuka, Hiroshi Kobayashi, Kenji Hasegawa

    ASTROPHYSICAL JOURNAL   Vol. 836 ( 2 )   2017.2

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    Recent radio observations show that giant molecular cloud (GMC) mass functions noticeably vary across galactic disks. High-resolution magnetohydrodynamics simulations show that multiple episodes of compression are required for creating a molecular cloud in the magnetized interstellar medium. In this article, we formulate the evolution equation for the GMC mass function to reproduce the observed profiles, for which multiple compressions are driven by a network of expanding shells due to H II regions and supernova remnants. We introduce the cloudcloud collision (CCC) terms in the evolution equation in contrast to previous work (Inutsuka et al.). The computed time evolution suggests that the GMC mass function slope is governed by the ratio of GMC formation timescale to its dispersal timescale, and that the CCC effect is limited only in the massive end of the mass function. In addition, we identify a gas resurrection channel that allows the gas dispersed by massive stars to regenerate GMC populations or to accrete onto pre-existing GMCs. Our results show that almost all of the dispersed gas contributes to the mass growth of pre-existing GMCs in arm regions whereas less than 60% contributes in inter-arm regions. Our results also predict that GMC mass functions have a single power-law exponent in the mass range < 10(5.5) M-circle dot (where M-circle dot represents the solar mass), which is well characterized by GMC self-growth and dispersal timescales. Measurement of the GMC mass function slope provides a powerful method to constrain those GMC timescales and the gas resurrecting factor in various environments across galactic disks.

    DOI: 10.3847/1538-4357/836/2/175

    Web of Science

  35. Sintering-induced Dust Ring Formation in Protoplanetary Disks: Application to the HL Tau Disk Reviewed

    Satoshi Okuzumi, Munetake Momose, Sin-iti Sirono, Hiroshi Kobayashi, Hidekazu Tanaka

    Astrophysical Journal   Vol. 821 ( 2 ) page: id 82, 24   2016.4

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  36. From Planetesimals to Planets in Turbulent Protoplanetary Disks. I. Onset of Runaway Growth Reviewed

    Hiroshi Kobayashi, Hidekazu Tanaka, Satoshi Okuzumi

    Astrophysical Journal   Vol. 817 ( 2 ) page: id. 105, 10   2016.2

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    DOI: 10.3847/0004-637X/817/2/105

    arXiv

  37. Comet C/2012 S1 (ISON) coma composition at ~4 au from HST observations Reviewed

    E. Zubko, G. Videen, D. C. Hines, Y. Shkuratov, V. Kaydash, K. Muinonen, M. M. Knight, M. L. Sitko, C. M. Lisse, M. Mutchler, D. H. Wooden, J.-Y. Li, H. Kobayashi

    Planetary and Space Science   Vol. 118   page: 138   2015.12

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  38. Resolution Dependence of Disruptive Collisions between Planetesimals in the Gravity Regime Reviewed

    H. Genda, T. Fujita, H. Kobayashi, H. Tanaka, Y. Abe

    Icarus   Vol. 262   page: 58   2015.12

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  39. Warm Debris Disks Produced by Giant Impacts During Terrestrial Planet Formation

    H. Genda, H. Kobayashi, E. Kokubo

    Astrophysical Journal   Vol. 810   page: 136(8p)   2015.11

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  40. Significant gas-to-dust ratio asymmetry and variation in the disk of HD 142527 and the indication of gas depletion

    Takayuki Muto, Takashi Tsukagoshi, Munetake Momose, Tomoyuki Hanawa, Hideko Nomura, Misato Fukagawa, Kazuya Saigo, Akimasa Kataoka, Yoshimi Kitamura, Sanemichi Z Takahashi, Shu-ichiro Inutsuka, Taku Takeuchi, Hiroshi Kobayashi, Eiji Akiyama, Mitsuhiko Honda, Hideaki Fujiwara, Hiroshi Shibai

    Publications of the Astronomical Society of Japan     page: psv098   2015.11

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  41. Cohesion of Amorphous Silica Spheres: Toward a Better Understanding of The Coagulation Growth of Silicate Dust Aggregates Reviewed

    Hiroshi Kimura, Koji Wada, Hiroki Senshu, Hiroshi Kobayashi

    Astrophysical Journal   Vol. 812   page: 1   2015.10

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  42. Planetary and meteoritic Mg/Si and δ30Si variations inherited from solar nebula chemistry Reviewed

    N. Dauphas, F. Poitrasson, C. Burkhardt, H. Kobayashi, K. Kurosawa

    Earth and Planetary Science Letter   Vol. 427   page: 236   2015.10

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  43. Formation of terrestrial planets in disks evolving via disk winds and implications for the origin of the solar system's terrestrial planets

    M. Ogihara, H. Kobayashi, S. Inutsuka, T. Suzuki

    Astronomy & Astrophysics   Vol. 579   page: A65   2015.6

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  44. Orbital Evolution of Planetesimals in Gaseous Disks

    Hiroshi Kobayashi

    Earth, Planets and Space   Vol. 67   page: 60   2015.4

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  45. Debris disc formation induced by planetary growth Reviewed

    Hiroshi Kobayashi, Torsten Loehne

    Monthly Notices of the Royal Astronomical Society   Vol. 442 ( 4 ) page: 464-8602   2014.8

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  46. N-body Simulations of Terrestrial Planet Formation under the Influence of a Hot Jupiter Reviewed

    Ogihara, Masahiro; Kobayashi, Hiroshi; Inutsuka, Shu-ichiro

    The Astrophysical Journal   Vol. 787 ( 2 ) page: id 172(16p)   2014.6

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  47. Local Enhancement of the Surface Density in the Protoplanetary Ring Surrounding HD 142527 Reviewed

    Fukagawa, Misato; Tsukagoshi, Takashi; Momose, Munetake; Saigo, Kazuya; Ohashi, Nagayoshi; Kitamura, Yoshimi; Inutsuka, Shu-ichiro; Muto, Takayuki; Nomura, Hideko; Takeuchi, Taku; Kobayashi, Hiroshi; Hanawa, Tomoyuki; Akiyama, Eiji; Honda, Mitsuhiko; Fujiwara, Hideaki; Kataoka, Akimasa; Takahashi, Sanemichi Z.; Shibai, Hiroshi

    Publications of the Astronomical Society of Japan   Vol. 65 ( 6 ) page: L14 (5p)   2013.12

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  48. Crowding-out of Giants by Dwarfs: An Origin for the Lack of Companion Planets in Hot Jupiter Systems Reviewed

    Ogihara, Masahiro; Inutsuka, Shu-ichiro; Kobayashi, Hiroshi

    The Astrophysical Journal Letters   Vol. 778 ( 1 ) page: id L9 (5p)   2013.11

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  49. Growth efficiency of dust aggregates through collisions with high mass ratios Reviewed

    Wada, Koji; Tanaka, Hidekazu; Okuzumi, Satoshi; Kobayashi, Hiroshi; Suyama, Toru; Kimura, Hiroshi; Yamamoto, Tetsuo

    Astronomy & Astrophysics   Vol. 559   page: id A62 (8p)   2013.11

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  50. Evolution of dust grain size distribution by shattering in the interstellar medium: Robustness and uncertainty Reviewed

    Hirashita, H.; Kobayashi, H.

    Earth, Planets and Space   Vol. 65 ( 10 ) page: 1083-1094   2013.10

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  51. Condition for Capture into First-order Mean Motion Resonances and Application to Constraints on the Origin of Resonant Systems Reviewed

    Ogihara, Masahiro; Kobayashi, Hiroshi

    The Astrophysical Journal   Vol. 775 ( 1 ) page: id 34 (12p)   2013.9

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  52. Small planetesimals in a massive disk formed Mars Reviewed

    Kobayashi, Hiroshi; Dauphas, Nicolas

    Icarus   Vol. 225 ( 1 ) page: 122-130   2013.7

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  53. Dust mantle of comet 9P/Tempel 1: dynamical constraints on physical properties Reviewed

    Kobayashi, H.; Kimura, H.; Yamamoto, S.

    Astronomy & Astrophysics   Vol. 550   page: id A72 (4p)   2013.2

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  54. Rapid Formation of Saturn after Jupiter Completion Reviewed

    Kobayashi, Hiroshi; Ormel, Chris W.; Ida, Shigeru

    The Astrophysical Journal   Vol. 756 ( 1 ) page: id 70 (7p)   2012.9

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  55. Rapid Coagulation of Porous Dust Aggregates outside the Snow Line: A Pathway to Successful Icy Planetesimal Formation Reviewed

    Okuzumi, Satoshi; Tanaka, Hidekazu; Kobayashi, Hiroshi; Wada, Koji

    The Astrophysical Journal   Vol. 752 ( 2 ) page: id 106 (18p)   2012.6

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  56. An improved model of the Edgeworth-Kuiper debris disk Reviewed

    Vitense, Ch.; Krivov, A. V.; Kobayashi, H.; Löhne, T.

    Astronomy & Astrophysics   Vol. 540   page: id A30 (10p)   2012.4

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  57. Understanding How Planets Become Massive. I. Description and Validation of a New Toy Model Reviewed

    Ormel, C. W.; Kobayashi, H.

    The Astrophysical Journal   Vol. 747 ( 2 ) page: id 115 (21p)   2012.3

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  58. 破壊が決める原始惑星の最終質量 Invited Reviewed

    小林浩

    日本惑星科学会誌「遊星人」   Vol. 20 ( 4 ) page: 317   2011.12

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  59. Sublimation temperature of circumstellar dust particles and its importance for dust ring formation Reviewed

    Kobayashi, H.; Kimura, H.; Watanabe, S.-i.; Yamamoto, T.; Müller, S.

    Earth, Planets and Space   Vol. 63 ( 10 ) page: 1067-1075   2011.10

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  60. Planetary Core Formation with Collisional Fragmentation and Atmosphere to Form Gas Giant Planets Reviewed

    Kobayashi, Hiroshi; Tanaka, Hidekazu; Krivov, Alexander V.

    The Astrophysical Journal   Vol. 738 ( 1 ) page: id 35 (11p)   2011.9

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  61. Planetary growth with collisional fragmentation and gas drag Reviewed

    Kobayashi, Hiroshi; Tanaka, Hidekazu; Krivov, Alexander V.; Inaba, Satoshi

    Icarus   Vol. 209 ( 2 ) page: 836-847   2010.10

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  62. Fragmentation model dependence of collision cascades Reviewed

    Kobayashi, Hiroshi; Tanaka, Hidekazu

    Icarus   Vol. 206 ( 2 ) page: 735-746   2010.4

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  63. Planets in orbit around β Pictoris formed the orbital architecture of planetesimal belts? Reviewed

    Kimura, H.; Fukagawa, M.; Tamura, M.; Kobayashi, H.; Yamamoto, T.; Ishii, M.; Suto, H.

    Earth, Planets and Space   Vol. 62 ( 1 ) page: 111-116   2010.1

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  64. Collisional process on Comet 9/P Tempel 1: mass loss of its dust and ice by impacts of asteroidal objects and its collisional history Reviewed

    Yamamoto, S.; Wada, K.; Kobayashi, H.; Kimura, H.; Ishiguro, M.; Matsui, T.

    Earth, Planets and Space   Vol. 62 ( 1 ) page: 5-11   2010.1

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  65. Ice sublimation of dust particles and their detection in the outer solar system Reviewed

    Kobayashi, H.; Kimura, H.; Yamamoto, S.; Watanabe, S.-I.; Yamamoto, T.

    Earth, Planets and Space   Vol. 62 ( 1 ) page: 57-61   2010.1

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  66. Dust ring formation due to sublimation of dust grains drifting radially inward by the Poynting-Robertson drag: An analytical model Reviewed

    Kobayashi, Hiroshi; Watanabe, Sei-ichiro; Kimura, Hiroshi; Yamamoto, Tetsuo

    Icarus   Vol. 201 ( 1 ) page: 395-405   2009.5

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  67. Dust ring formation due to ice sublimation of radially drifting dust particles under the Poynting Robertson effect in debris disks Reviewed

    Kobayashi, Hiroshi; Watanabe, Sei-ichiro; Kimura, Hiroshi; Yamamoto, Tetsuo

    Icarus   Vol. 195 ( 2 ) page: 871-881   2008.6

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  68. 太陽系外縁天体の起源と進化 Invited Reviewed

    小林浩

    日本惑星科学会誌「遊星人」   Vol. 17 ( 1 ) page: 22   2008.3

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  69. Comet 9P/Tempel 1: Interpretation with the Deep Impact Results Reviewed

    Yamamoto, Satoru; Kimura, Hiroshi; Zubko, Evgenij; Kobayashi, Hiroshi; Wada, Koji; Ishiguro, Masateru; Matsui, Takafumi

    The Astrophysical Journal   Vol. 673 ( 2 ) page: L199-L202   2008.2

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  70. The evidence of an early stellar encounter in Edgeworth Kuiper belt Reviewed

    Kobayashi, Hiroshi; Ida, Shigeru; Tanaka, Hidekazu

    Icarus   Vol. 177 ( 1 ) page: 246-255   2005.9

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  71. Percolation-fission model study of the 1 GeV proton-induced reaction on Pb 208 targets Reviewed

    M Katsuma, H Kobayashi, T Sasa, T Sawada

    Physical Review C   Vol. 71 ( 4 ) page: 044605   2005.4

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  72. なぜ海王星以遠では惑星がないのか? Reviewed

    小林 浩,井田 茂

    日本惑星科学会誌「遊星人」   Vol. 10 ( 4 ) page: 208   2001.12

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  73. The Effects of a Stellar Encounter on a Planetesimal Disk Reviewed

    Kobayashi, Hiroshi; Ida, Shigeru

    Icarus   Vol. 153 ( 2 ) page: 416-429   2001.10

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Books 1

  1. 系外惑星の辞典

    青木和光,阿部 豊,生駒大洋,石川遼子,石渡正樹,井田 茂,伊藤祐一,上野雄一郎,臼井寛裕,大西紀和,大宮正士,奥住 聡,門屋辰太郎,木村 淳,葛原昌幸,國友正信,黒崎健二,玄田英典,洪  鵬,小久保英一郎,小谷隆行,小玉貴則,小林 浩,小宮 剛,佐々木貴教,佐藤文衛,渋谷岳造,須田拓馬,住 貴宏,関根康人,千秋博紀,空華智子,髙田将郎,高橋 太,髙橋康人,竹内 拓,竹田洋一,田近英一,橘 省吾,舘野繁彦,田中秀和,田村元秀,長澤真樹子,中本泰史,成田憲保,はしもとじょーじ,橋本 淳,羽馬哲也,濱野景子,原川紘季,原田真理子,樋口有理可,平林 久,深川美里,福井暁彦,藤井友香,藤原英明,堀 安範,前田太郎,増田賢人,町田正博,松尾太郎,眞山 聡,武藤恭之,村上 豪,百瀬宗武,森島龍司,安井千香子 東京大学 矢野太平,薮田ひかる,山岸明彦,山口正輝,吉田 敬( Role: Joint author)

    2016.9 

MISC 8

  1. Impact erosion model for gravity-dominated planetesimals Reviewed

    Hidenori Genda, Tomoaki Fujita, Hiroshi Kobayashi, Hidekazu Tanaka, Ryo Suetsugu, Yutaka Abe

    ICARUS   Vol. 294   page: 234 - 246   2017.9

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:ACADEMIC PRESS INC ELSEVIER SCIENCE  

    Disruptive collisions have been regarded as an important process for planet formation, while non disruptive, small-scale collisions (hereafter called erosive collisions) have been underestimated or neglected by many studies. However, recent studies have suggested that erosive collisions are also important to the growth of planets, because they are much more frequent than disruptive collisions. Although the thresholds of the specific impact energy for disruptive collisions (Q(RD)*) have been investigated well, there is no reliable model for erosive collisions. In this study, we systematically carried out impact simulations of gravity-dominated planetesimals for a wide range of specific impact energy (Q(R)) from disruptive collisions (Q(R)similar to Q(RD)*) to erosive ones (Q(R)<<R-D*) using the smoothed particle hydrodynamics method. We found that the ejected mass normalized by the total mass (M-ej/M-tot) depends on the numerical resolution, the target radius (R-tar) and the impact velocity (v(imp)), as well as on Q(R), but that it can be nicely scaled by Q(RD)* for the parameter ranges investigated (Rtar =30-300 km, v(imp) =2-5 km/s). This means that Mej/Mtot depends only on Q(R)/Q(RD)* in these parameter ranges. We confirmed that the collision outcomes for much less erosive collisions (Q(R) <0.01 Q(RD)*) converge to the results of an impact onto a planar target for various impact angles (theta) and that Mej/Mtot cc proportional to Q(R)/Q(RD)* holds. For disruptive collisions (Q(R)similar to QRD*), the curvature of the target has a significant effect on Mej/Mtot. We also examined the angle-averaged value of Mej/Mtot and found that the numerically obtained relation between angle-averaged M-ej/M-tot and Q(R)/Q(RD)* is very similar to the cases for theta=45 degrees impacts. We proposed a new erosion model based on our numerical simulations for future research on planet formation with collisional erosion. (C) 2017 Elsevier Inc. All rights reserved.

    DOI: 10.1016/j.icarus.2017.03.009

    Web of Science

  2. A likely detection of a local interplanetary dust cloud passing near the Earth in the AKARI mid-infrared all-sky map

    D. Ishihara, T. Kondo, H. Kaneda, T. Suzuki, K. Nakamichi, S. Takaba, H. Kobayashi, S. Masuda, T. Ootsubo, J. Pyo, T. Onaka

    ASTRONOMY & ASTROPHYSICS   Vol. 603   2017.7

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    Context. We are creating the AKARI mid-infrared all-sky diffuse maps. Through a foreground removal of the zodiacal emission, we serendipitously detected a bright residual component whose angular size is about 50 degrees x 20 degrees at a wavelength of 9 mu m.
    Aims. We investigate the origin and the physical properties of the residual component.
    Methods. We measured the surface brightness of the residual component in the AKARI mid-infrared all-sky maps.
    Results. The residual component was significantly detected only in 2007 January, even though the same region was observed in 2006 July and 2007 July, which shows that it is not due to the Galactic emission. We suggest that this may be a small cloud passing near the Earth. By comparing the observed intensity ratio of I-9 mu m/I-18 mu m with the expected intensity ratio assuming thermal equilibrium of dust grains at 1 AU for various dust compositions and sizes, we find that dust grains in the moving cloud are likely to be much smaller than typical grains that produce the bulk of the zodiacal light.
    Conclusions. Considering the observed date and position, it is likely that it originates in the solar coronal mass ejection ( CME) which took place on 2007 January 25.

    DOI: 10.1051/0004-6361/201628954

    Web of Science

  3. Faint warm debris disks around nearby bright stars explored by AKARI and IRSF Reviewed

    Daisuke Ishihara, Nami Takeuchi, Hiroshi Kobayashi, Takahiro Nagayama, Hidehiro Kaneda, Shu-ichiro Inutsuka, Hideaki Fujiwara, Takashi Onaka

    ASTRONOMY & ASTROPHYSICS   Vol. 601   page: A72   2017.5

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    Context. Debris disks are important observational clues for understanding planetary-system formation process. In particular, faint warm debris disks may be related to late planet formation near 1 au. A systematic search of faint warm debris disks is necessary to reveal terrestrial planet formation.
    Aims. Faint warm debris disks show excess emission that peaks at mid-IR wavelengths. Thus we explore debris disks using the AKARI mid-IR all-sky point source catalog (PSC), a product of the second generation unbiased IR all-sky survey.
    Methods. We investigate IR excess emission for 678 isolated main-sequence stars for which there are 18 mu m detections in the AKARI mid-IR all-sky catalog by comparing their fluxes with the predicted fluxes of the photospheres based on optical to near-IR fluxes and model spectra. The near-IR fluxes are first taken from the 2MASS PSC. However, 286 stars with Ks < 4.5 in our sample have large flux errors in the 2MASS photometry due to saturation. Thus we have measured accurate J, H, and Ks band fluxes, applying neutral density (ND) filters for Simultaneous InfraRed Imager for Unbiased Survey (SIRIUS) on IRSF, the phi 1.4m near-IR telescope in South Africa, and improved the flux accuracy from 14% to 1.8% on average.
    Results. We identified 53 debris-disk candidates including eight new detections from our sample of 678 main-sequence stars. The detection rate of debris disks for this work is similar to 8%, which is comparable with those in previous works by Spitzer and Herschel.
    Conclusions. The importance of this study is the detection of faint warm debris disks around nearby field stars. At least nine objects have a large amount of dust for their ages, which cannot be explained by the conventional steady-state collisional cascade model.

    DOI: 10.1051/0004-6361/201526215

    Web of Science

  4. Faint warm debris disks around nearby bright stars explored by AKARI and IRSF

    Daisuke Ishihara, Nami Takeuchi, Hiroshi Kobayashi, Takahiro Nagayama, Hidehiro Kaneda, Shu-ichiro Inutsuka, Hideaki Fujiwara, Takashi Onaka

    ASTRONOMY & ASTROPHYSICS   Vol. 601   2017.5

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:EDP SCIENCES S A  

    Context. Debris disks are important observational clues for understanding planetary-system formation process. In particular, faint warm debris disks may be related to late planet formation near 1 au. A systematic search of faint warm debris disks is necessary to reveal terrestrial planet formation.
    Aims. Faint warm debris disks show excess emission that peaks at mid-IR wavelengths. Thus we explore debris disks using the AKARI mid-IR all-sky point source catalog (PSC), a product of the second generation unbiased IR all-sky survey.
    Methods. We investigate IR excess emission for 678 isolated main-sequence stars for which there are 18 mu m detections in the AKARI mid-IR all-sky catalog by comparing their fluxes with the predicted fluxes of the photospheres based on optical to near-IR fluxes and model spectra. The near-IR fluxes are first taken from the 2MASS PSC. However, 286 stars with Ks < 4.5 in our sample have large flux errors in the 2MASS photometry due to saturation. Thus we have measured accurate J, H, and Ks band fluxes, applying neutral density (ND) filters for Simultaneous InfraRed Imager for Unbiased Survey (SIRIUS) on IRSF, the phi 1.4m near-IR telescope in South Africa, and improved the flux accuracy from 14% to 1.8% on average.
    Results. We identified 53 debris-disk candidates including eight new detections from our sample of 678 main-sequence stars. The detection rate of debris disks for this work is similar to 8%, which is comparable with those in previous works by Spitzer and Herschel.
    Conclusions. The importance of this study is the detection of faint warm debris disks around nearby field stars. At least nine objects have a large amount of dust for their ages, which cannot be explained by the conventional steady-state collisional cascade model.

    DOI: 10.1051/0004-6361/201526215

    Web of Science

  5. Detection of Submillimeter-wave [CI] Emission in Gaseous Debris Disks of 49 Ceti and beta Pictoris Reviewed

    Aya E. Higuchi, Aki Sato, Takashi Tsukagoshi, Nami Sakai, Kazunari Iwasaki, Munetake Momose, Hiroshi Kobayashi, Daisuke Ishihara, Sakae Watanabe, Hidehiro Kaneda, Satoshi Yamamoto

    ASTROPHYSICAL JOURNAL LETTERS   Vol. 839 ( 1 ) page: L14   2017.4

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    We have detected [C I] P-3(1)-P-3(0) emissions in the gaseous debris disks of 49 Ceti and beta Pictoris with the 10 m telescope of the Atacama Submillimeter Telescope Experiment, which is the first detection of such emissions. The line profiles of [C I] are found to resemble those of CO(J = 3-2) observed with the same telescope and the Atacama Large Millimeter/submillimeter Array. This result suggests that atomic carbon (C) coexists with CO in the debris disks. and is likely formed by the photodissociation of CO. Assuming an optically thin [C I] emission with the excitation temperature ranging from 30 to 100. K, the column density of C is evaluated to be (2.2 +/- 0.2). x. 10(17) and (2.5 +/- 0.7). x. 10(16). cm(-2) for 49 Ceti and beta Pictoris, respectively. The C/CO column density ratio is thus derived to be 54 +/- 19 and 69 +/- 42 for 49 Ceti and beta Pictoris, respectively. These ratios are higher than those of molecular clouds and diffuse clouds by an order of magnitude. The unusually high ratios of C to CO are likely attributed to a lack of H-2 molecules needed to reproduce CO molecules efficiently from C. This result implies a small number of H-2 molecules in the gas disk,. i.e., there is an appreciable contribution of secondary gas from dust grains.

    DOI: 10.3847/2041-8213/aa67f4

    Web of Science

  6. Detection of Submillimeter-wave [CI] Emission in Gaseous Debris Disks of 49 Ceti and beta Pictoris

    Aya E. Higuchi, Aki Sato, Takashi Tsukagoshi, Nami Sakai, Kazunari Iwasaki, Munetake Momose, Hiroshi Kobayashi, Daisuke Ishihara, Sakae Watanabe, Hidehiro Kaneda, Satoshi Yamamoto

    ASTROPHYSICAL JOURNAL LETTERS   Vol. 839 ( 1 )   2017.4

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We have detected [C I] P-3(1)-P-3(0) emissions in the gaseous debris disks of 49 Ceti and beta Pictoris with the 10 m telescope of the Atacama Submillimeter Telescope Experiment, which is the first detection of such emissions. The line profiles of [C I] are found to resemble those of CO(J = 3-2) observed with the same telescope and the Atacama Large Millimeter/submillimeter Array. This result suggests that atomic carbon (C) coexists with CO in the debris disks. and is likely formed by the photodissociation of CO. Assuming an optically thin [C I] emission with the excitation temperature ranging from 30 to 100. K, the column density of C is evaluated to be (2.2 +/- 0.2). x. 10(17) and (2.5 +/- 0.7). x. 10(16). cm(-2) for 49 Ceti and beta Pictoris, respectively. The C/CO column density ratio is thus derived to be 54 +/- 19 and 69 +/- 42 for 49 Ceti and beta Pictoris, respectively. These ratios are higher than those of molecular clouds and diffuse clouds by an order of magnitude. The unusually high ratios of C to CO are likely attributed to a lack of H-2 molecules needed to reproduce CO molecules efficiently from C. This result implies a small number of H-2 molecules in the gas disk,. i.e., there is an appreciable contribution of secondary gas from dust grains.

    DOI: 10.3847/2041-8213/aa67f4

    Web of Science

  7. Evolutionary Description of Giant Molecular Cloud Mass Functions on Galactic Disks

    Masato I. N. Kobayashi, Shu-ichiro Inutsuka, Hiroshi Kobayashi, Kenji Hasegawa

    ASTROPHYSICAL JOURNAL   Vol. 836 ( 2 )   2017.2

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    Recent radio observations show that giant molecular cloud (GMC) mass functions noticeably vary across galactic disks. High-resolution magnetohydrodynamics simulations show that multiple episodes of compression are required for creating a molecular cloud in the magnetized interstellar medium. In this article, we formulate the evolution equation for the GMC mass function to reproduce the observed profiles, for which multiple compressions are driven by a network of expanding shells due to H II regions and supernova remnants. We introduce the cloudcloud collision (CCC) terms in the evolution equation in contrast to previous work (Inutsuka et al.). The computed time evolution suggests that the GMC mass function slope is governed by the ratio of GMC formation timescale to its dispersal timescale, and that the CCC effect is limited only in the massive end of the mass function. In addition, we identify a gas resurrection channel that allows the gas dispersed by massive stars to regenerate GMC populations or to accrete onto pre-existing GMCs. Our results show that almost all of the dispersed gas contributes to the mass growth of pre-existing GMCs in arm regions whereas less than 60% contributes in inter-arm regions. Our results also predict that GMC mass functions have a single power-law exponent in the mass range < 10(5.5) M-circle dot (where M-circle dot represents the solar mass), which is well characterized by GMC self-growth and dispersal timescales. Measurement of the GMC mass function slope provides a powerful method to constrain those GMC timescales and the gas resurrecting factor in various environments across galactic disks.

    DOI: 10.3847/1538-4357/836/2/175

    Web of Science

  8. Evolutionary Description of Giant Molecular Cloud Mass Functions on Galactic Disks Reviewed

    Masato I. N. Kobayashi, Shu-ichiro Inutsuka, Hiroshi Kobayashi, Kenji Hasegawa

    ASTROPHYSICAL JOURNAL   Vol. 836 ( 2 ) page: 175   2017.2

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    Language:English   Publishing type:Rapid communication, short report, research note, etc. (scientific journal)   Publisher:IOP PUBLISHING LTD  

    Recent radio observations show that giant molecular cloud (GMC) mass functions noticeably vary across galactic disks. High-resolution magnetohydrodynamics simulations show that multiple episodes of compression are required for creating a molecular cloud in the magnetized interstellar medium. In this article, we formulate the evolution equation for the GMC mass function to reproduce the observed profiles, for which multiple compressions are driven by a network of expanding shells due to H II regions and supernova remnants. We introduce the cloudcloud collision (CCC) terms in the evolution equation in contrast to previous work (Inutsuka et al.). The computed time evolution suggests that the GMC mass function slope is governed by the ratio of GMC formation timescale to its dispersal timescale, and that the CCC effect is limited only in the massive end of the mass function. In addition, we identify a gas resurrection channel that allows the gas dispersed by massive stars to regenerate GMC populations or to accrete onto pre-existing GMCs. Our results show that almost all of the dispersed gas contributes to the mass growth of pre-existing GMCs in arm regions whereas less than 60% contributes in inter-arm regions. Our results also predict that GMC mass functions have a single power-law exponent in the mass range < 10(5.5) M-circle dot (where M-circle dot represents the solar mass), which is well characterized by GMC self-growth and dispersal timescales. Measurement of the GMC mass function slope provides a powerful method to constrain those GMC timescales and the gas resurrecting factor in various environments across galactic disks.

    DOI: 10.3847/1538-4357/836/2/175

    Web of Science

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Presentations 21

  1. 微惑星形成・天体形成/移動 Invited

    小林浩

    始原天体ワークショップ  2022.3.16 

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    Event date: 2022.3

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン  

  2. Early Formation of Gas-Giant Planets Revealed by Dust-to-Planet Simulations

    2022.3.14 

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    Event date: 2022.3

    Language:Japanese   Presentation type:Oral presentation (general)  

  3. Early Formation of Jupiter Revealed by Dust-to-Planet Simulations Invited

    2022.3.7 

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    Event date: 2022.3

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

  4. 巨大衝突起源のデブリ円盤の特徴解明に向けた巨大衝突シミュレーション

    小林浩

    日本天文学会2022年春季年会  2022.3.3  日本天文学会

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    Event date: 2022.3

    Language:Japanese   Presentation type:Poster presentation  

    Venue:オンライン  

  5. 地球型惑星形成にともなう大気獲得とその組成進化についての理論的研究

    小林浩

    第5回 新学術領域研究「水惑星学」全体会議  2022.3.1  新学術領域研究「水惑星学」

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    Event date: 2022.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  6. 巨大ガス惑星の コア形成理論

    小林浩

    新学術「星・惑星形成」A02A03合同会議  2022.2.17  新学術領域研究「星・惑星形成」A02班、A03班

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    Event date: 2022.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  7. ダストから惑星への統一シミュレーションによる巨大ガス惑星形成

    小林浩、田中秀和

    日本惑星科学会秋季講演会  2021.9.17  日本惑星科学会

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    Event date: 2021.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  8. ダストから惑星まで統一シミュレーション:巨大ガス惑星形成と軌道の分布

    小林浩、田中秀和

    日本天文学会2021年秋季年会  2021.9.14  日本天文学会

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    Event date: 2021.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  9. The Collisional History in the Main Belt International conference

    Hiroshi Kobayashi

    Japan Geoscience Union Meeting 2021  2021.6.6 

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    Event date: 2021.5 - 2021.6

    Language:English   Presentation type:Oral presentation (invited, special)  

    Venue:online  

  10. 原始惑星重力下での 原始惑星系円盤ガスの流れと小天体の衝突率

    小林浩、岡村達弥

    日本天文学会2021年春季年会  2021.3.17  日本天文学会

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    Event date: 2021.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  11. 惑星形成と氷微惑星の移動

    小林浩

    第4回 新学術領域研究「水惑星学」全体会議  2021.3.8  新学術領域「水惑星」

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    Event date: 2021.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:金沢大学(オンライン)  

  12. Dust in Planet Formation Invited International conference

    Hiroshi Kobayashi

    PERC Int'l Symposium on Dust & Parent Bodies 2021  2021.2.10 

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    Event date: 2021.2

    Language:English   Presentation type:Oral presentation (invited, special)  

  13. 惑星形成の衝突史解明に向けた はやぶさ2のデータの重要性 Invited

    小林浩

    「惑星形成過程とはやぶさ2探査」研究会  2021.1.13 

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    Event date: 2021.1

    Language:Japanese   Presentation type:Oral presentation (invited, special)  

    Venue:オンライン  

  14. ダストから惑星まで成長を取り扱う 大統一シミュレーション

    小林浩、田中秀和

    2020年理論懇シンポジウム  2020.12.24  理論天文学宇宙物理学懇談会

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    Event date: 2020.12

    Language:Japanese   Presentation type:Poster presentation  

    Venue:オンライン  

  15. ダストから惑星まで直接合体成長を取り扱う統一シミュレーション

    小林浩、田中秀和

    2020年度惑星科学会秋季講演会  2020.11.14  日本惑星科学会

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    Event date: 2020.11

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン   Country:Japan  

  16. 原始惑星系円盤中でのダストから惑星まで一貫した直接合体成長の理論的研究

    小林浩、田中秀和

    日本天文学会2020年秋季年会  2020.9.10  日本天文学会

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    Event date: 2020.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン   Country:Japan  

  17. 原始惑星重力下での原始惑星系円盤ガスの流れと小天体の衝突率

    岡村達弥、小林浩

    日本天文学会2020年秋季年会  2020.9.10  日本天文学会

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    Event date: 2020.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン   Country:Japan  

  18. ダストから惑星への直接合体成長とALMAで観測される原始惑星系円盤の進化

    小林 浩、大橋 聡史

    JpGU -AGU Joint Meeting 2020  2020.7.15 

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    Event date: 2020.7

    Language:Japanese   Presentation type:Poster presentation  

  19. Numerical Simulations of Spinup of Asteroids and the Formation of Top-Shaped Asteroids

    2020.7 

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    Event date: 2020.7

    Language:Japanese   Presentation type:Poster presentation  

  20. Collisional Growth and Fragmentation of Dust Aggregates with Low to Very High Mass Ratios

    2020.7.15 

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    Event date: 2020.7

    Language:Japanese   Presentation type:Poster presentation  

  21. 地球型惑星形成にともなう大気獲得とその組成進化についての理論的研究

    小林浩

    新学術「水惑星学」公募班キックオフミーティング  2020.5.11  新学術領域「水惑星」

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    Event date: 2020.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

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KAKENHI (Grants-in-Aid for Scientific Research) 10

  1. Terrestrial Planet Formation with Collisional Fragmentation

    Grant number:21K03642  2021.4 - 2025.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

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    Authorship:Principal investigator 

    Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )

  2. Theory on planetary-atmosphere acquisition and evolution during planet formation

    Grant number:20H04612  2020.4 - 2022.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

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    Authorship:Principal investigator 

    Grant amount:\2600000 ( Direct Cost: \2000000 、 Indirect Cost:\600000 )

  3. Theory for the Formation of Planetary Systems from Diverse Protoplanetary Disks

    Grant number:18H05438  2018.6 - 2023.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

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    Authorship:Coinvestigator(s) 

  4. A Paradigm Shift by a Novel Theory of Star Formation: Exploration of Habitable Planetary Systems in Our Galaxy

    Grant number:18H05436  2018.6 - 2023.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

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    Authorship:Coinvestigator(s) 

  5. Multicolor anatomy of protorplanetary disks: Towards understanding of planet formation

    Grant number:17H01103  2017.4 - 2022.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

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    Authorship:Coinvestigator(s) 

  6. Evolution of protoplanetary discs and planet formation with magnetically driven disc winds

    Grant number:17H01105  2017.4 - 2022.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

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    Authorship:Coinvestigator(s) 

  7. Modeling of collisional growth from dust to planets

    Grant number:17K05632  2017.4 - 2021.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    Kobayashi Hiroshi

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    Authorship:Principal investigator 

    Grant amount:\4420000 ( Direct Cost: \3400000 、 Indirect Cost:\1020000 )

    Planets are formed from submicron-sized dust grains in a protoplanetary disk. In previous studies, the collisional evolution in a limited mass range, such as only among dust grains or among planetesimals. However, the importance of the wide mass range interaction such as protoplanets and pebbles is argued. Therefore, we develop a simulation code to treat the collisional evolution from dust grains to planet, whose mass range is more than 40 orders of magnitude. As the result of the simulation, we show cores of gas giant planets are formed in several hundred thousand years.

  8. Theoretical study on an unified process of planetesimal formation and accumulation

    Grant number:22540242  2010 - 2012

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    TANAKA Hidekazu, KOBAYASHI Hiroshi

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    Authorship:Other 

    We investigated the growth process from dust grains to planetesimals and their radial migration, taking into account the evolution of their internal density. Because of their radial migration, solid bodies are concentrated inside of 10AU and grow to km-sized planetesimals. In this planetesimal-forming region, the surface density of the solid component is enhanced by a factor of ~10, compared with the original value. The growing solid bodies have a highly porous structure, which helps their growth to planetesimals. The large enhancement in the solid surface density accelerates growth of cores of Jovian planets.

  9. Infrared Spectra of Comets as a Barometer for Their Evolution

    Grant number:21340040  2009.4 - 2014.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    KIMURA Hiroshi, KOBAYASHI Hiroshi, WADA Koji

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    Authorship:Collaborating Investigator(s) (not designated on Grant-in-Aid) 

    We have found that the fractal dimension of aggregated dust particles in comets determines the strength of peaks characteristic of olivine detected in the infrared spectra of dust in cometary comae, while the volume fraction and carbonization of organic refractory material in the dust aggregates play an important role in the determination of the peak wavelengths. Furthermore, both an increase in the fractal dimension and the carbonization of organic refractory material are associated with the formation of a dust mantle on the surface of a comet. Therefore, the infrared spectra of cometary comae can be regarded as a barometer of the evolution of comets as well as the alteration of comet grain properties. Since the processing of comet dust proceeds with the orbit of the parent-body comet, we expect that a thorough analysis of infrared data will reveal a correlation between the spectral features characteristic of olivine and the orbital semi-major axes of comets.

  10. Modelling of Collisional Disruption of Planetary Bodies via Large-scale Numerical Simulations

    Grant number:26287101  2014.4 - 2018.3

    Tanaka Hidekazu

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    Authorship:Coinvestigator(s) 

    In this work, by performing a large-scale survey of numerical simulations, we constructed an accurate and unified model of collisional disruption, which is a key process in various studies of planetary sciences. As the numerical methods, we used three kinds of methods, i.e., a SPH code, a mesh (iSALE) code, and a DEM code, which enable us to obtain the total ejecta mass at various impacts for planetary bodies with a wide size range from km-size to 1000km-size.
    <BR>
    Clarifying the resolution dependence of the collisional disruption, we developed the method to calculate the convergent value at high-resolution limit. From a survey of accurate numerical simulations applied this method to, we obtain a new scaling law of the total ejecta mass, which is valid for a wide range of parameters (sizes of colliding bodies, the impact velocity, and the angle) and succeeded in modelling the collisional disruption. We also applied this new model to Jovian planets formation and obtained constraints on it.

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Teaching Experience (On-campus) 2

  1. 物理学演習2

    2021

  2. 物理学演習2

    2020