Updated on 2024/03/23

写真a

 
MATSUO Taro
 
Organization
Graduate School of Science Associate professor
Graduate School
Graduate School of Science
Undergraduate School
School of Science Department of Physics
Title
Associate professor
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私は「生命とは何か?、なぜ、私たちは誕生したのか?」という問いに対して、宇宙から地球を俯瞰しながら、また地球を一つの生命が存在する惑星として捉えながら、その問いに迫りたいと考えています。その問いに迫る第一歩が宇宙における生命探査だと考えています。しかし、その実現には多くの技術的課題が残されています。私は、このような技術的課題にはブレークスルーが欠かせないと考えており、新しいアイデアやアプローチを試行錯誤しながら、実現したいと考えています。新しい学問の誕生には、一つの学問からの発展では困難です。従来の学問の領域・壁を超えて、生物学・植物学・惑星科学の研究者らと連携しながら、この問いに迫りたいと考えています。最終的には、様々な国や人との交流を通して、そのフロンティアを開拓していきます。
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Degree 1

  1. 博士(理学) ( 2008.3   名古屋大学 ) 

Research Interests 5

  1. High Contrast Spectroscopic Imaging for Characterizing Earth-like Planets

  2. Spectroscopy of Earth-like Planet Candidates

  3. Planetary Formation

  4. Formation Flight Infrared Space Interferometer

  5. Highly Stable Spectrograph for Characterizing Transiting Exoplanets

Research Areas 1

  1. Natural Science / Astronomy  / Astrobiology, spectroscopy

Research History 3

  1. Nagoya University   School of Science Department of Physics   Associate professor

    2019.11

  2. NASA Ames Research Center   Space Science and Astrobiology Division   Visiting Researcher

    2018.6

  3. Osaka University   Graduate School of Science Department of Earth and Space Science   Assistant Professor

    2015.10 - 2019.10

Professional Memberships 2

  1. 生命の起原と進化学会

    2022.4

  2. 天文学会

    2010.4

Committee Memberships 7

  1. University of Tokyo   TAO Scientific Advisory Comittee  

    2022.9   

  2. 生命の起原進化学会   夏の学校座長  

    2022.8   

  3. Group of Optical and Infrared Astronomers   Committee for Japanese Astronomical Roadmap in the 2030s  

    2018.4   

  4. Group of Optical and Infrared Astronomers   Committee for Optical and Infrared Space Projects in the 2030’s  

    2017.4 - 2018.3   

  5. National Astronomical Observatory of Japan   Time Allocation Commitee for Okayama 188cm Telescope  

    2014.4 - 2018.3   

  6. Thirty Meter Telescope   Thirty Meter Telescope, International Science Development Team  

    2013.4 - 2017.3   

  7. Thirty Meter Telescope   International Science Advisory Committee  

    2013.4 - 2017.3   

▼display all

 

Papers 46

  1. Wide-Spectral-Band Nuller Insensitive to Finite Stellar Angular Diameter with a One-Dimensional Diffraction-Limited Coronagraph Reviewed

    Itoh, S., Matsuo, T., Tamura, M.

    Astronomical Journal     2024

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

  2. Large Interferometer For Exoplanets (LIFE): XI. Phase-space synthesis decomposition for planet detection and characterization

    Matsuo T., Dannert F., Laugier R., Quanz S.P., Kovačeviäč A.B.

    Astronomy and Astrophysics   Vol. 678   2023.10

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    Publisher:Astronomy and Astrophysics  

    Context. A mid-infrared nulling-space interferometer offers a promising way to characterize thermal light from habitable planet candidates around Sun-like stars. However, one of the main challenges inherent in achieving this ambitious goal is the high-precision stability of the optical path difference and amplitude over a few days for planet detections and all the way up to a few weeks for in-depth characterization. This is related to mission parameters such as aperture size, number of apertures, and total instrument throughput. Aims. Here, we propose a new method called phase-space synthesis decomposition (PSSD) to shorten the stability requirement to a scale of minutes, significantly relaxing the technological challenges of the mission. Methods. By focusing on the consideration of what exactly modulates the planetary signal in the presence of the stellar leak and systematic error, PSSD prioritizes the modulation of the signals along the wavelength domain rather than baseline rotation. Modulation along the wavelength domain allows us to extract source positions in parallel to the baseline vector for each exposure. The sum of the one-dimensional data is converted into two-dimensional information. Based on the reconstructed image, we constructed a continuous equation and extract the spectra through the singular value decomposition, while efficiently separating them from a long-term systematic stellar leak. Results. We performed numerical simulations to investigate the feasibility of PSSD for the Large Interferometer For Exoplanets (LIFE) mission concept. We confirm that multiple terrestrial planets in the habitable zone around a Sun-like star at 10 pc can be detected and characterized despite high levels and long durations of systematic noise. We also find that PSSD is more robust against a sparse sampling of the array rotation compared to purely rotation-based signal extraction. Using PSSD as signal extraction method significantly relaxes the technical requirements on the signal stability and further increases the feasibility of the LIFE mission.

    DOI: 10.1051/0004-6361/202345927

    Scopus

  3. Experimental Verification of a One-dimensional Diffraction-limit Coronagraph

    Itoh S., Matsuo T., Ota S., Hara K., Ikeda Y., Kojima R., Yamada T., Sumi T.

    Publications of the Astronomical Society of the Pacific   Vol. 135 ( 1048 )   2023.6

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    Publisher:Publications of the Astronomical Society of the Pacific  

    We performed an experimental verification of a coronagraph. As a result, we confirmed that, at the focal region where the planetary point spread function exists, the coronagraph system mitigates the raw contrast of a star-planet system by at least 1 × 10−5 even for the 1-λ/D star-planet separation. In addition, the verified coronagraph keeps the shapes of the off-axis point spread functions when the setup has the source angular separation of 1λ/D. The low-order wave front error and the non-zero extinction ratio of the linear polarizer may affect the currently confirmed contrast. The sharpness of the off-axis point spread function generated by the sub-λ/D separated sources is promising for the fiber-based observation of exoplanets. The coupling efficiency with a single mode fiber exceeds 50% when the angular separation is greater than 3-4×10−1 λ/D. For sub-λ/D separated sources, the peak positions (obtained with Gaussian fitting) of the output point spread functions are different from the angular positions of sources; the peak position moved from about 0.8λ/D to 1.0λ/D as the angular separation of the light source varies from 0.1λ/D to 1.0λ/D. The off-axis throughput including the fiber-coupling efficiency (with respect to no focal plane mask) is about 40% for 1-λ/D separated sources and 10% for 0.5-λ/D separated ones (excluding the factor of the ratio of pupil aperture width and Lyot stop width), where we assumed a linear-polarized-light injection. In addition, because this coronagraph can remove point sources on a line in the sky, it has another promising application for high-contrast imaging of exoplanets in binary systems.

    DOI: 10.1088/1538-3873/acdbea

    Scopus

  4. Development of high-precision spectrograph for diffraction-limited coronagraphs

    S. Ota, T. Matsuo, S. Itoh, T. Kano, Y. Ikeda, R. Kojima, T. Sukegawa, T. Nakayasu, M. Koyama, T. Sumi, T. Yamada

    Proceedings of SPIE - The International Society for Optical Engineering     2022.8

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

    The atmospheric characterization of habitable candidates is one of the effective approaches for search for life out of the solar system. However, it is much hard by high planet-star flux contrast, 10-8 - 10-10 . A coronagraphic mask proposed by Itoh & Matsuo (2020) can suppress host stellar light but is imposed by a strict wavelength range limit of 0.3%. A spectroscopic coronagraph that combines the diffraction-limited coronagraph with a spectrograph is expected to achieve enlarges the effective bandwidth. On the other hand, a non-common path error, which is induced by the spectrograph, could limit the achievable contrast. We designed a high-accuracy spectrograph motivated for the spectroscopic coronagraph and measured its wavefront error. The common path error is 9.9 nm RMS, which is mostly caused by the alignment error between the convex grating and spherical mirror of the spectrograph. The achievable contrast of the spectroscopic coronagraph was also estimated from the non-common path error measurement. We found that the contrast of 10-8 could be achieved with a bandwidth of 5%, which is a promising result as the first step.

  5. High spatial resolution spectral imaging method for space interferometers and its application to formation flying small satellites Reviewed

    Taro Matsuo, Satoshi Ikari, Hirotaka Kondo, Sho Ishiwata, Shinichi Nakasuka, Tomoyasu Yamamuro

    Journal of Astronomical Telescopes, Instruments, and Systems   Vol. 8   2022.2

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

    DOI: https://doi.org/10.1117/1.JATIS.8.1.015001

  6. Densified Pupil Spectrograph as High-precision Radial Velocimetry: From Direct Measurement of the Universe's Expansion History to Characterization of Nearby Habitable Planet Candidates

    Matsuo T., Greene T.P., Qezlou M., Bird S., Ichiki K., Fujii Y., Yamamuro T.

    Astronomical Journal   Vol. 163 ( 2 )   2022.2

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    Language:Japanese   Publisher:Astronomical Journal  

    The direct measurement of the universe's expansion history and the search for terrestrial planets in habitable zones around solar-type stars require extremely high-precision radial-velocity measures over a decade. This study proposes an approach for enabling high-precision radial-velocity measurements from space. The concept presents a combination of a high-dispersion densified pupil spectrograph and a novel line-of-sight monitor for telescopes. The precision of the radial-velocity measurements is determined by combining the spectrophotometric accuracy and the quality of the absorption lines in the recorded spectrum. Therefore, a highly dispersive densified pupil spectrograph proposed to perform stable spectroscopy can be utilized for high-precision radial-velocity measures. A concept involving the telescope's line-of-sight monitor is developed to minimize the change of the telescope's line of sight over a decade. This monitor allows the precise measurement of long-term telescope drift without any significant impact on the Airy disk when the densified pupil spectra are recorded. We analytically derive the uncertainty of the radial-velocity measurements, which is caused by the residual offset of the lines of sight at two epochs. We find that the error could be reduced down to approximately 1 cm s-1, and the precision will be limited by another factor (e.g., wavelength calibration uncertainty). A combination of the high-precision spectrophotometry and the high spectral resolving power could open a new path toward the characterization of nearby non-transiting habitable planet candidates orbiting late-type stars. We present two simple and compact highly dispersed densified pupil spectrograph designs for cosmology and exoplanet sciences.

    DOI: 10.3847/1538-3881/ac397b

    Scopus

  7. High spatial resolution spectral imaging method for space interferometers and its application to formation flying small satellites

    Matsuo T., Ikari S., Kondo H., Ishiwata S., Nakasuka S., Yamamuro T.

    Journal of Astronomical Telescopes, Instruments, and Systems   Vol. 8 ( 1 )   2022.1

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    Publisher:Journal of Astronomical Telescopes, Instruments, and Systems  

    Infrared space interferometers can surpass the spatial resolution limitations of single-dish space telescopes. However, stellar interferometers from space have not been realized because of technical difficulties. Two beams coming from individual satellites separated by more than a few tens of meters should precisely interfere such that the optical-path and angular differences between the two beams are reduced at the wavelength level. Herein, we propose a unique beam combiner for space interferometers that records the spectrally resolved interferometric fringes using the densified pupil spectroscopic technique. As the detector plane is optically conjugated to a plane, on which the two beams interfere, we can directly measure the relative phase difference between the two beams. Additionally, when an object within the field of view is obtained with a modest signal-to-noise ratio, we can extract the true complex amplitude from a continuous broadband fringe (i.e., one exposure measurement), without scanning a delay line and chopping interferometry. We discovered that this spectral imaging method is validated for observing the solar system objects by simulating the reflected light from Europa with a small stellar interferometer. However, because the structure of the object spectrum may cause a systematic error in the measurement, this method may be limited in extracting the true complex amplitude for other astronomical objects. Applying this spectral imaging method to general astrophysics will facilitate further research. The beam combiner and spectral imaging method are applied to a formation flying stellar interferometer with multiple small satellites in a Sun-synchronous orbit, named Space Experiment of InfraRed Interferometric Observation Satellite (SEIRIOS), for observation of the solar system objects in visible and near-infrared. We present an overview of SEIRIOS and the optimized optical design for a limited-volume spacecraft.

    DOI: 10.1117/1.JATIS.8.1.015001

    Scopus

  8. The Japan-United States Infrared Interferometry Experiment (JUStIInE): Balloon-borne pathfinder for a space-based far-IR interferometer

    Leisawitz D., Matsuo T., Mosby G., Ade P., Akeson R., Fixsen D., Gong Q., Kaneda H., Maher S.F., Mundy L.G., Ota S., Rau G., Sharp E., Shimokawa T., Staguhn J., Tucker C., Van Belle G.

    Proceedings of SPIE - The International Society for Optical Engineering   Vol. 12190   2022

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    Publisher:Proceedings of SPIE - The International Society for Optical Engineering  

    The balloon-borne Japan-United States Infrared Interferometry Experiment (JUStIInE) is a pathfinder for the first space-based far-IR interferometer. JUStIInE will mature the system-level technology readiness of spatio-spectral far-IR interferometry and demonstrate this technique with scientific observations. Operating at wavelengths from 30 to 90 μm, JUStIInE will provide unprecedented sub-Arcsecond angular resolution and spectroscopic data. Our plan is to develop a cryogenic Michelson beam combiner and integrate it with an existing and tested telescope optical system and gondola from the Japanese Far-infrared Interferometric Telescope Experiment (FITE). With two JUStIInE balloon flights we plan to collect, calibrate, analyze, and publish scientific results based on the first far-IR spatio-spectral observations of young stellar objects, evolved stars, and the active galactic nucleus of NGC 1068. The NASA Astrophysics Roadmap envisages a future in which interferometry is applied across the electromagnetic spectrum, starting in the far-infrared. The Far-IR Probe recommended in the 2021 Decadal Survey presents an opportunity to take that important step. A Far-IR Probe mission based on this concept will enable us to understand terrestrial planet formation and spectroscopically study individual distant galaxies to understand the astrophysical processes that govern their evolution.

    DOI: 10.1117/12.2629426

    Scopus

  9. Development progress of diffraction-limited coronagraphs with moderate spectral bandwidths

    Itoh S., Matsuo T., Ota S., Ikeda Y., Kojima R., Yamada T., Sumi T.

    Proceedings of SPIE - The International Society for Optical Engineering   Vol. 12188   2022

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    Publisher:Proceedings of SPIE - The International Society for Optical Engineering  

    Recently, we have proposed a fourth-order coronagraph with inner working angles (IWA) of ∼1λ/D applicable with segmented telescopes, by deriving some complex-valued focal-plane mask patterns with the value between the interval [-1,1]. The mask pattern is implementable achromatically with a custom-patterned half-waveplate sandwiched between two linear polarizers orthogonal to each other. To enhance the system's spectral bandwidth, we are now investigating the methods from various perspectives. One method to widen the system's spectral bandwidth is to disperse point spread functions (PSF) incident to the focal-plane mask to the direction orthogonal to the mask pattern using a diffraction grating. Because the mask pattern is one-dimensional, we can optimize the mask pattern for each PSF dispersed by each wavelength (spectroscopic coronagraph). Another method focuses on the fact that the stellar leak due to a wide spectral bandwidth is flat at the Lyot stop and thus reducible with the successive use of the multiple coronagraph systems. Because the practical successive use of the multiple coronagraph systems requires a high off-axis throughput of the focal-plane mask, we derived new mask patterns by modifying the original pattern. This method can bring additional enhance of spatial resolution, although the current optimization limits the working angle to the separation angles of 0.7-1.4λ/D (super-resolution coronagraph or double coronagraph). Our fundamental simulation shows that both the methods can deliver a contrast of 10-10 at wavelengths of 650-750nm.

    DOI: 10.1117/12.2629087

    Scopus

  10. A Coronagraph with a Sub- λ/ D Inner Working Angle and a Moderate Spectral Bandwidth

    Itoh S., Matsuo T.

    Astronomical Journal   Vol. 163 ( 6 )   2022

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    Publisher:Astronomical Journal  

    Future high-contrast imaging spectroscopy with a large segmented telescope will be able to detect atmospheric molecules of Earth-like planets around G- or K-type main-sequence stars. Increasing the number of target planets will require a coronagraph with a small inner working angle (IWA), and wide spectral bandwidth is required if we enhance a variety of detectable atmospheric molecules. To satisfy these requirements, in this paper, we present a coronagraphic system that provides an IWA less than 1λ 0/D over a moderate wavelength band, where λ 0 is the design-center wavelength and D denotes the full width of the rectangular aperture included in the telescope aperture. A performance simulation shows that the proposed system approximately achieves a contrast below 10-10 at 1λ 0/D over the wavelengths of 650-750 nm. In addition, this system has a core throughput ≥10% at input separation angles of ∼0.7-1.4λ 0/D; to reduce telescope time, we need prior information on the target's orbit by other observational methods to a precision higher than the width of the field of view. For some types of aberration including tilt aberration, the proposed system has a sensitivity less than ever-proposed coronagraphs that have IWAs of approximately 1λ 0/D. In future observations of Earth-like planets, the proposed coronagraphic system may serve as a supplementary coronagraphic system dedicated to achieving an extremely small IWA.

    DOI: 10.3847/1538-3881/ac658a

    Scopus

  11. Polarimetric signature of the oceans as detected by near-infrared Earthshine observations

    Takahashi J., Itoh Y., Matsuo T., Oasa Y., Bach Y.P., Ishiguro M.

    Astronomy and Astrophysics   Vol. 653   2021.9

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    Language:Japanese   Publisher:Astronomy and Astrophysics  

    Context. The discovery of an extrasolar planet with an ocean has crucial importance in the search for life beyond Earth. The polarimetric detection of specularly reflected light from a smooth liquid surface is anticipated theoretically, though the polarimetric signature of Earth's oceans has not yet been conclusively detected in disk-integrated planetary light. Aims. We aim to detect and measure the polarimetric signature of the Earth's oceans. Methods. We conducted near-infrared polarimetry for lunar Earthshine and collected data on 32 nights with a variety of ocean fractions in the Earthshine-contributing region. Results. A clear positive correlation was revealed between the polarization degree and ocean fraction. We found hourly variations in polarization in accordance with rotational transition of the ocean fraction. The ratios of the variation to the typical polarization degree were as large as ~0.2-1.4. Conclusions. Our observations provide plausible evidence of the polarimetric signature attributed to Earth's oceans. Near-infrared polarimetry may be considered a prospective technique in the search for exoplanetary oceans.

    DOI: 10.1051/0004-6361/202039331

    Scopus

  12. Detecting Atmospheric Molecules of Nontransiting Temperate Terrestrial Exoplanets Using High-resolution Spectroscopy in the Mid-infrared Domain

    Fujii Y., Matsuo T.

    Astronomical Journal   Vol. 161 ( 4 )   2021.4

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    Language:Japanese   Publisher:Astronomical Journal  

    Motivated by the development of high-dispersion spectrographs in the mid-infrared (MIR) range, we study their application to the atmospheric characterization of nearby nontransiting temperate terrestrial planets around M-type stars. We examine the detectability of CO2, H2O, N2O, and O3 features in high-resolution planetary thermal emission spectra at 12-18 μm assuming an Earth-like profile and a simplified thermal structure. The molecular line width of such planets can be comparable to or broader than the Doppler shift due to the planetary orbital motion. Given the likely difficulty in knowing the high-resolution MIR spectrum of the host star with sufficient accuracy, we propose observing the target system at two quadrature phases and extracting the differential spectra as the planetary signal. In this case, the signals can be substantially suppressed compared with the case where the host star spectrum is perfectly known, as some parts of the spectral features do not remain in the differential spectra. Despite this self-subtraction, the CO2 and H2O features of nearby (≲5 pc) systems with mid-/late-M host stars would be feasible with a 6.5 m class cryogenic space telescope, and orbital inclination could also be constrained for some of them. For CO2 and N2O in a 1 bar Earth-like atmosphere, this method would be sensitive when the mixing ratio is 1-103 ppm. The detectability of molecules except O3 is not significantly improved when the spectral resolution is higher than R10,000, although the constraint on the orbital inclination is improved. This study provides some benchmark cases useful for assessing the value of MIR high-resolution spectroscopy in terms of characterization of potentially habitable planets.

    DOI: 10.3847/1538-3881/abe129

    Scopus

  13. Detecting Atmospheric Molecules of Nontransiting Temperate Terrestrial Exoplanets Using High-resolution Spectroscopy in the Mid-infrared Domain Reviewed

    Y. Fujii T. Matsuo

    Astronomical Journal   Vol. 161   page: 180   2021.3

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

    DOI: https://doi.org/10.3847/1538-3881/abe129

  14. Spectroscopic fourth-order coronagraph for the characterization of terrestrial planets at small angular separations from host stars

    Matsuo T., Itoh S., Ikeda Y.

    Astronomical Journal   Vol. 161 ( 2 )   2021.2

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    Language:Japanese   Publisher:Astronomical Journal  

    We propose a new approach for high-contrast imaging at the diffraction limit using segmented telescopes in a modest observation bandwidth. This concept, named "spectroscopic fourth-order coronagraphy,"is based on a fourth-order coronagraph with a focal-plane mask that modulates the complex amplitude of the Airy disk along one direction. While coronagraphs applying the complex amplitude mask can achieve the theoretical limit performance for any arbitrary pupils, the focal-plane mask severely limits the bandwidth. Here, focusing on the fact that the focal-plane mask modulates the complex amplitude along one direction, we noticed that the mask can be optimized for each spectral element generated by a spectrograph. We combine the fourth-order coronagraph with two spectrographs to produce a stellar spectrum on the focal plane and reconstruct a white pupil on the Lyot stop. Based on the wave-front analysis of an optical design applying an Offner-type imaging spectrograph, we found that the achievable contrast of this concept is 10-10-10 at 1.2-1.5 times the diffraction limit over the wavelength range of 650-750 nm for the entrance pupil of the LUVOIR telescope. Thus, this coronagraph concept could bring new habitable planet candidates not only around G- and K-type stars beyond 20-30 pc but also around very nearby M-type stars. This approach potentially promotes the characterization of the atmospheres of nearby terrestrial planets with future on- and off-axis segmented large telescopes.

    DOI: 10.3847/1538-3881/abd248

    Web of Science

    Scopus

  15. Mid-infrared spectrometer and camera for the Origins Space Telescope

    Sakon I., Roellig T.L., Ennico-Smith K., Matsuo T., Ikeda Y., Yamamuro T., Enya K., Wada T., Kawada M., Takahashi A., Sarugaku Y., Fujishiro N., Murakami N., Nishikawa J., Kotani T., Goda S., Ido M., Itoh S., Tsuboi T., Sumi T., Kamiura M., Manome T., Iida N., Yanagibashi K., Greene T., Helvensteijn B., Hofland L., Johnson R., Kashani A., Quigley E., McMurray R., Inami H., Burgarella D.

    Journal of Astronomical Telescopes, Instruments, and Systems   Vol. 7 ( 1 )   2021.1

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    Language:Japanese   Publisher:Journal of Astronomical Telescopes, Instruments, and Systems  

    The mid-infrared spectrometer and camera transit spectrometer (MISC-T) is one of the three baseline instruments for Origins Space Telescope (Origins) and provides the capability to assess the habitability of nearby exoplanets and search for signs of life. MISC-T employs a densified pupil optical design, and HgCdTe and Si:As detector arrays. This optical design allows the instrument to be relatively insensitive to minor line-of-sight pointing drifts and telescope aberrations, and the detectors do not require a sub-Kelvin refrigerator. MISC-T has three science spectral channels that share the same field-of-view by means of beam splitters, and all channels are operated simultaneously to cover the full spectral range from 2.8 to 20 μm at once with exquisite stability and precision (<5 ppm between 2.8 to 11 μm, <20 ppm between 11 and 20 μm). A Lyot-coronagraph-based tip-tilt sensor located in the instrument fore-optics uses the light reflected by a field stop, which corresponds to 0.3% of the light from the target, to send fine pointing information to the field steering mirror in the Origins telescope. An additional MISC Wide Field Imager (WFI) is studied as an upscope option for the Origins. MISC-WFI offers a wide field imaging (3′ × 3′) and low-resolution spectroscopic capability with filters and grating-prisms (grisms) covering 5 to 28 μm. The imaging capability of the MISC-WFI will be used for general science objectives. The low-resolution spectroscopic capability in MISC-WFI with a resolving power R (= λ/Δλ) of a few hundreds will be used to measure the mid-infrared dust features and ionic lines at z up to 1/41 in the Origins mission's Rise of Metals and Black Hole Feedback programs. The MISC-WFI also serves as a focal plane pointing and guiding instrument for the observatory, including when the MISC-T channel is performing its exoplanet spectroscopy observations.

    DOI: 10.1117/1.JATIS.7.1.011013

    Scopus

  16. Mid-infrared detector development for the Origins Space Telescope Invited Reviewed International coauthorship

    T. Roellig, C. MucMarty, T. Greene, T. Matsuo, I. Sakon, J. Staguhn

    Journal of Astronomical Telescopes, Instruments, and Systems   Vol. 6   2020.10

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

    DOI: 10.1117/1.JATIS.6.4.041503

  17. OGLE-2017-BLG-0406: ${\it Spitzer}$ Microlens Parallax Reveals Saturn-mass Planet orbiting M-dwarf Host in the Inner Galactic Disk

    Yuki Hirao, David P. Bennett, Yoon-Hyun Ryu, Naoki Koshimoto, Andrzej Udalski, Jennifer C. Yee, Takahiro Sumi, Ian A. Bond, Yossi Shvartzvald, Fumio Abe, Richard K. Barry, Aparna Bhattacharya, Martin Donachie, Akihiko Fukui, Yoshitaka Itow, Iona Kondo, Man Cheung Alex Li, Yutaka Matsubara, Taro Matsuo, Shota Miyazaki, Yasushi Muraki, Masayuki Nagakane, Clement Ranc, Nicholas J. Rattenbury, Haruno Suematsu, Hiroshi Shibai, Daisuke Suzuki, Paul J. Tristram, Atsunori Yonehara, J. Skowron, R. Poleski, P. Mroz, M. K. Szymanski, I. Soszynski, S. Kozlowski, P. Pietrukowicz, K. Ulaczyk, K. Rybicki, P. Iwanek, Michael D. Albrow, Sun-Ju Chung, Andrew Gould, Cheongho Han, Kyu-Ha Hwang, Youn Kil Jung, In-Gu Shin, Weicheng Zang, Sang-Mok Cha, Dong-Jin Kim, Hyoun-Woo Kim, Seung-Lee Kim, Chung-Uk Lee, Dong-Joo Lee, Yongseok Lee, Byeong-Gon Park, Richard W. Pogge, Charles A. Beichman, Geoffery Bryden, Sebastiano Calchi Novati, Sean Carey, B. Scott Gaudi, Calen B. Henderson, Wei Zhu, Etienne Bachelet, Greg Bolt, Grant Christie, Markus Hundertmark, Tim Natusch, Dan Maoz, Jennie McCormick, Rachel A. Street, Thiam-Guan Tan, Yiannis Tsapras, U. G. Jorgensen, M. Dominik, V. Bozza, J. Skottfelt, C. Snodgrass, S. Ciceri, R. Figuera Jaimes, D. F. Evans, N. Peixinho, T. C. Hinse, M. J. Burgdorf, J. Southworth, S. Rahvar, S. Sajadian, M. Rabus, C. von Essen, Y. I. Fujii, J. Campbell-White, S. Lowry, C. Helling, L. Mancini, L. Haikala, Ryo Kandori

      Vol. 160 ( 2 )   2020.8

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    Language:Japanese  

    We report the discovery and analysis of the planetary microlensing event
    OGLE-2017-BLG-0406, which was observed both from the ground and by the ${\it
    Spitzer}$ satellite in a solar orbit. At high magnification, the anomaly in the
    light curve was densely observed by ground-based-survey and follow-up groups,
    and it was found to be explained by a planetary lens with a planet/host mass
    ratio of $q=7.0 \times 10^{-4}$ from the light-curve modeling. The ground-only
    and ${\it Spitzer}$-"only" data each provide very strong one-dimensional (1-D)
    constraints on the 2-D microlens parallax vector $\bf{\pi_{\rm E } }$. When
    combined, these yield a precise measurement of $\bf{\pi_{\rm E } }$, and so of
    the masses of the host $M_{\rm host}=0.56\pm0.07\,M_\odot$ and planet $M_{\rm
    planet} = 0.41 \pm 0.05\,M_{\rm Jup}$. The system lies at a distance $D_{\rm
    L}=5.2 \pm 0.5 \ {\rm kpc}$ from the Sun toward the Galactic bulge, and the
    host is more likely to be a disk population star according to the kinematics of
    the lens. The projected separation of the planet from the host is $a_{\perp} =
    3.5 \pm 0.3 \ {\rm au}$, i.e., just over twice the snow line. The Galactic-disk
    kinematics are established in part from a precise measurement of the source
    proper motion based on OGLE-IV data. By contrast, the ${\it Gaia}$
    proper-motion measurement of the source suffers from a catastrophic
    $10\,\sigma$ error.

    DOI: 10.3847/1538-3881/ab9ac3

    Web of Science

    Scopus

    arXiv

  18. Fourth-order Coronagraph for High-contrast Imaging of Exoplanets with Off-axis Segmented Telescopes Reviewed

    Satoshi Itoh, Taro Matsuo

    ASTRONOMICAL JOURNAL   Vol. 159 ( 5 )   2020.5

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We propose a coronagraphic system with fourth-order null for off-axis segmented telescopes, which is sufficiently insensitive to the telescope pointing errors and finite angular diameter of the host star to enable high-contrast imaging of potentially habitable planets. The inner working angle of the coronagraphic system is close to 1 lambda/D, and there is no outer limit. The proposed coronagraphic system is made up of a new focal plane mask and an optimized Lyot stop with the second-order null. The new focal plane mask is an extension of the band-limited masks with a phase modulation. We construct a coronagraphic system with fourth-order null by placing two of the new coronagraph systems in succession to be orthogonal to each other. The proposed system is limited to narrow-band usage. The characteristics of the proposed coronagraph system are derived analytically, which includes (1) the leak of stellar lights due to the finite stellar diameter and pointing jitter of a telescope, and (2) the peak throughput. We achieve the performance simulations of this coronagraphic system based on these analytical expressions, considering a monochromatic light of 0.75 mu m and an off-axis primary mirror with a diameter of 8.5 m. Thanks to the wide working area of the mask, the result shows that terrestrial planets orbiting K and G dwarfs can be detected under the condition that the telescope pointing jitter is less than 0.01 lambda/D 240 as. The proposed coronagraphic system is promising for the detection of potentially habitable planets with future space off-axis hexagonally segmented telescopes.

    DOI: 10.3847/1538-3881/ab811c

    Web of Science

    Scopus

    arXiv

  19. Optical Adjustment of the FITE Interferometer Reviewed

    Ayana Sasaki, Hiroshi Shibai, Taro Matsuo, Takahiro Sumi, Satoshi Itoh, Teruhira Ohyama, Yoshito Tani, Morito Saiki, Takahiro Tsuboi, Masanao Narita

    JOURNAL OF ASTRONOMICAL INSTRUMENTATION   Vol. 9 ( 1 )   2020.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:WORLD SCIENTIFIC PUBL CO PTE LTD  

    We have developed a balloon-borne far-infrared interferometer, the Far-infrared Interferometric Telescope Experiment (FITE). The final goal of spatial resolution was one arcsec at 100 mu m. As a first step, we aimed to achieve a spatial resolution of five arcsecs at 155 mu m with a 6-m baseline. FITE is a two-beam interferometer like Michelsons stellar interferometer. Positions and attitudes of all mirrors required to have their alignment checked and possibly adjusted before launch and were checked during observation. We had to satisfy three requirements: the coincidence of the phases of each beam (wavefront error), image quality of the two beams at the (common) focus, and no optical path difference between the two beams for celestial objects. In order to achieve the former two requirements, we developed an interferometer adjustment system that used a newly-developed interferometer measurement instrument. This instrument adopted a Shack-Hartmann wavefront sensor to measure wavefront errors of the two off-axis parabolic mirrors, simultaneously. With this system, the adjustment of the FITE interferometer was carried out at the Alice Springs balloon base in Australia as the JAXA's Australia balloon experiment campaign of 2018. On-site adjustment was successful; wavefront errors of the two off-axis parabolic mirrors were 1.78 mu m and 4.99 mu m (peak-to-valley), and the Hartmann constant was 13 arcsecs. As for the optical path difference, we achieved the requirement by step-wise displacement of a folding plane mirror. Results satisfied the requirements for an interferometer designed for a wavelength of 155 mu m. Improvement of spatial resolution at far-infrared wavelengths is undoubtedly important for research on protoplanetary disks, circumstellar dust shells of late-type stars, and star-forming galaxies. The method we have developed is also useful for future space interferometers.

    DOI: 10.1142/S2251171720500026

    Web of Science

  20. OGLE-2013-BLG-0911Lb: A Secondary on the Brown-dwarf Planet Boundary around an M Dwarf Reviewed

    Miyazaki S., Sumi T., Bennett D.P., Bennett D.P., Udalski A., Shvartzvald Y., Street R., Bozza V., Yee J.C., Bond I.A., Rattenbury N., Koshimoto N., Suzuki D., Fukui A., Fukui A., Abe F., Bhattacharya A., Bhattacharya A., Barry R., Donachie M., Fujii H., Hirao Y., Itow Y., Kamei Y., Kondo I., Li M.C.A., Ling C.H., Matsubara Y., Matsuo T., Muraki Y., Nagakane M., Ohnishi K., Ranc C., Saito T., Sharan A., Shibai H., Suematsu H., Sullivan D.J., Tristram P.J., Yamakawa T., Yonehara A., Skowron J., Poleski R., Mróz P., Mróz P., Szymaski M.K., Soszyski I., Pietrukowicz P., Kozowski S., Ulaczyk K., Wyrzykowski , Friedmann M., Kaspi S., Maoz D., Albrow M., Christie G., Depoy D.L., Gal-Yam A., Gould A., Gould A., Gould A., Lee C.U., Fr C., Manulis I., McCormick J., Natusch T., Natusch T., Ngan H., Pogge R.W., Porritt I., Tsapras Y., Bachelet E., Bachelet E., Hundertmark M.P.G., Dominik M., Bramich D.M., Cassan A., Jaimes R.F., Jaimes R.F., Horne K., Schmidt R., Snodgrass C., Wambsganss J., Steele I.A., Menzies J., Mao S., Jørgensen U.G., Burgdorf M.J., Ciceri S., Novati S.C., D'Ago G., D'Ago G., D'Ago G., Evans D.F., Hinse T.C., Kains N.

    Astronomical Journal   Vol. 159 ( 2 )   2020.2

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Astronomical Journal  

    We present the analysis of the binary-lens microlensing event OGLE-2013-BLG-0911. The best-fit solutions indicate the binary mass ratio of q ? 0.03, which differs from that reported in Shvartzvald et al. The event suffers from the well-known close/wide degeneracy, resulting in two groups of solutions for the projected separation normalized by the Einstein radius of s ? 0.15 or s ? 7. The finite source and the parallax observations allow us to measure the lens physical parameters. The lens system is an M dwarf orbited by a massive Jupiter companion at very close separation. Although the mass ratio is slightly above the planet-brown dwarf (BD) mass-ratio boundary of q = 0.03, which is generally used, the median physical mass of the companion is slightly below the planet-BD mass boundary of 13MJup. It is likely that the formation mechanisms for BDs and planets are different and the objects near the boundaries could have been formed by either mechanism. It is important to probe the distribution of such companions with masses of ?13MJup in order to statistically constrain the formation theories for both BDs and massive planets. In particular, the microlensing method is able to probe the distribution around low-mass M dwarfs and even BDs, which is challenging for other exoplanet detection methods.

    DOI: 10.3847/1538-3881/ab64de

    Web of Science

    Scopus

  21. High-resolution Near-infrared Polarimetry and Submillimeter Imaging of FS Tau A: Possible Streamers in Misaligned Circumbinary Disk System Reviewed

    Yi Yang, Eiji Akiyama, Thayne Currie, Ruobing Dong, Jun Hashimoto, Saeko S. Hayashi, Carol A. Grady, Markus Janson, Nemanja Jovanovic, Taichi Uyama, Takao Nakagawa, Tomoyuki Kudo, Nobuhiko Kusakabe, Masayuki Kuzuhara, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Michael Bonnefoy, Joseph C. Carson, Jeffrey Chilcote, Evan A. Rich, Markus Feldt, Miwa Goto, Tyler D. Groff, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Ryo Kandori, Jeremy Kasdin, Gillian R. Knapp, Jungmi Kwon, Julien Lozi, Frantz Martinache, Taro Matsuo, Satoshi Mayama, Michael W. Mcelwain, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martin, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Hiroshi Suto, Ryuji Suzuki, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Edwin L. Turner, Makoto Watanabe, John P. Wisniewski, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura

    ASTROPHYSICAL JOURNAL   Vol. 889 ( 2 )   2020.2

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We analyzed the young (2.8 Myr-old) binary system FS Tau A using near-infrared (H-band) high -contrast polarimetry data from Subaru/HiCIAO and submillimeter CO (J = 2-1) line emission data from Atacama Large Millimeter/submillimeter Array (ALMA). Both the near-infrared and submillimeter observations reveal several clear structures extending to similar to 240 au from the stars. Based on these observations at different wavelengths, we report the following discoveries. One arm-like structure detected in the near-infrared band initially extends from the south of the binary with a subsequent turn to the northeast, corresponding to two bar-like structures detected in ALMA observations with an local standard of rest kinematic (LSRK) velocity of 1.19-5.64 km s(-1). Another feature detected in the near-infrared band extends initially from the north of the binary, relating to an arm-like structure detected in ALMA observations with an LSRK velocity of 8.17-16.43 km s(-1). From their shapes and velocities, we suggest that these structures can mostly be explained by two streamers that connect the outer circumbinary disk and the central binary components. These discoveries will be helpful for understanding the evolution of streamers and circumstellar disks in young binary systems.

    DOI: 10.3847/1538-4357/ab64f9

    Web of Science

    arXiv

  22. The mid-infrared spectrometer/camera (MISC) for the Origins Space Telescope Reviewed

    Sakon I., Roellig T.L., Ennico-Smith K., Matsuo T., Ikeda Y., Yamamuro T., Enya K.

    Proceedings of SPIE - The International Society for Optical Engineering   Vol. 11443   2020

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Proceedings of SPIE - The International Society for Optical Engineering  

    The Mid-Infrared Spectrometer (Camera) transit spectrometer (MISC-T) is one of the baseline instruments studied for the Origins Space Telescope. MISC-T employs a novel densified pupil optical design and achieves exquisite stability and precision (<5ppm in 2.8 - 11μm, <20ppm in 11 - 20μm). It provides the Origins with the capability to assess the habitability of nearby exoplanets and search for signs of life. An additional MISC Wide Field Imager (MISC-WFI) is studied as an upsope option for the Origins. MISC-WFI offers an imaging and low-resolution spectroscopic capability for 5 - 28μm. The MISC WFI also serves as the focal plane pointing and guiding for the observatory.

    DOI: 10.1117/12.2561949

    Scopus

  23. Laboratory experiment of densified pupil spectrograph for the Origins Space Telescope Reviewed

    Matsuo T., Greene T.P., Johnson R.R., Mcmurray R.E., Roellig T., Ennico-Smith K., Helvensteijn B.P., Kashani A., Shibai H., Sumi T., Itoh S., Sakon I., Yamamuro T., Ikeda Y., Manome T., Iida N., Yanagibashi K., Kamiura M.

    Proceedings of SPIE - The International Society for Optical Engineering   Vol. 11443   2020

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Proceedings of SPIE - The International Society for Optical Engineering  

    We report on the laboratory experiments of a densified pupil spectrograph designed for mid-infrared transit spectroscopy of exoplanets. We developed a testbed consisting of a blackbody infrared light source, a densified pupil spectrograph, and a prototype JWST Si:As Impurity Band Conduction (IBC) detector array to simulate observations of a planet's host star. In order to thermally stabilize the measurement system, we installed all of the components in a large cryogenic dewar and controlled the temperatures of the thermal source and the Si:As IBC detector. The characteristics of the spectrum formed on the detector were consistent with the designed values. The photometric precision of the densified pupil spectrograph was 14 ppm on average over the whole observing wavelength range of 8.5 to 10.5 μm. The systematic noise component of the spectrograph hidden behind the transit spectrograph was 11 ppm.

    DOI: 10.1117/12.2560421

    Scopus

  24. Identification of infrared-ring structures by convolutional neural network Reviewed

    Ueda S., Fujita S., Nishimura A., Onishi T., Shimajiri Y., Miyamoto Y., Torii K., Ito A.M., Takekawa S., Kaneko H., Yoshida D., Matsuo T., Inoue T., Kawanishi Y., Tokuda K.

    Proceedings of SPIE - The International Society for Optical Engineering   Vol. 11452   2020

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    Publishing type:Research paper (scientific journal)   Publisher:Proceedings of SPIE - The International Society for Optical Engineering  

    Recently, the amount of data obtained from astronomical instruments has been increasing explosively, and data science methods such as Machine Learning/Deep Learning gain attention on the back of the growth in demand for automatic analysis. Using these methods, the number of applications to the target sources that have clear boundaries with the background i.e., stars, planets, and galaxies is increasing year by year. However, there are a few studies which applied the data science methods to the interstellar medium (ISM) distributed in the Galactic plane, which have complicated and ambiguous silhouettes. We aim to develop classifiers to automatically extract various structures of the ISM by Convolutional Neural Network (CNN) that is strong in image recognition even in deep learning. In this study, we focus on the infra-red (IR) ring structures distributed in the Galactic plane. Based on the catalog of Churchwell et al. (2006, 2007), we created a "Ring"dataset from the Spitzer/GLIMPSE 8 μm and Spitzer/MIPSGAL 24 μm data and optimized the parameters of the CNN model. We applied the developed model to a range of 16.5° ≤ l ≤ 19.5°, |b| ≤ 1°. As a result, 234 "Ring"candidates are detected. The "Ring"candidates were matched with 75%Milky Way Project (MWP, Simpson et al. 2012) "Ring"and 65%WISE Hii region catalog (Anderson et al. 2014). In addition, new"Ring"and Hii region candidate objects were also found. For these results, we conclude that the CNN model may have a recognition accuracy equal to or better than that of human eyes.

    DOI: 10.1117/12.2560830

    Scopus

  25. Photometric Precision of a Si:As Impurity Band Conduction Mid-infrared Detector and Application to Transit Spectroscopy Reviewed

    Taro Matsuo, Thomas P. Greene, Roy R. Johnson, Robert E. Mcmurray, Thomas L. Roellig, Kimberly Ennico

    PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC   Vol. 131 ( 1006 )   2019.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    Transit spectroscopy is the most promising path toward characterizing nearby terrestrial planets at mid-infrared (3?30 ?m) wavelengths in the next 20 yr. The Spitzer Space telescope has achieved moderately good mid-infrared photometric precision in observations of transiting planets, but the intrinsic photometric stability of mid-IR detectors themselves has not been reported in the scientific or technical literature. Here, we evaluated the photometric precision of a James Webb Space Telescope Mid-Infrared Instrument prototype mid-infrared Si:As impurity band conduction detector, using time-series data taken under flood illumination. These measurements of photometric precision were conducted over periods of ?10 hr, representative of the time required to observe an exoplanet transit. After selecting multiple sub-regions with a size of 10 & xfffd;& x5e0;10 pixels and compensating for a gain change caused by our warm detector control electronics for the selected sub-regions, we found that the photometric precision was limited to 26.3 ppm at high co-added signal levels due to a gain variation caused by our warm detector control electronics. The photometric precision was improved up to 12.8 ppm after correcting for the gain drift. We also translated the photometric precision to the expected spectro-photometric precision (i.e., relative photometric precision between wavelengths), assuming that an optimized densified pupil spectrograph is used in transit observations. We found that the spectro-photometric precision of an optimized densified pupil spectrograph when used in transit observations is expected to be improved by the square root of the number of pixels per a spectral resolution element. At the high co-added signal levels, the total noise could be reduced down to 7 ppm, which was larger by a factor of 1.3 than the ideal performance that was limited by the Poisson noise and readout noise. The systematic noise hidden behind the simulated transit spectroscopy was 1.7 ppm.

    DOI: 10.1088/1538-3873/ab42f1

    Web of Science

    arXiv

  26. OGLE-2015-BLG-1649Lb: A gas giant planet around a low-mass dwarf Reviewed

    Masayuki Nagakane, Chien-Hsiu Lee, Naoki Koshimoto, Daisuke Suzuki, Andrzej Udalski, Jean-Philippe Beaulieu, Takahiro Sumi, David Bennett, Ian A. Bond, Nicholas J. Rattenbury, Etienne Bachelet, Martin Dominik, Fumio Abe, Richard Barry, Aparna Bhattacharya, Martin Donachie, H. Fujii, Akihiko Fukui, Yuki Hirao, Yoshitaka Itow, Y. Kamei, Iona Kondo, Man Cheung Alex Li, Y. Matsubara, Taro Matsuo, Shota Miyazaki, Yasushi Muraki, Clément Ranc, Hiroshi Shibai, Haruno Suematsu, Denis Sullivan, P. Tristram, T. Yamakawa, A. Yonehara, P. Mróz, Radosław Poleski, Jan Skowron, M. Szymański, I. Soszyński, Pawel Pietrukowicz, Szymon Kozłowski, Krzysztof Ulaczyk, Dan Bramich, Arnaud Cassan, R. Jaimes, K. Horne, Markus Hundertmark, Shude Mao, John Menzies, R. Schmidt, Colin Snodgrass, Iain Steele, Rachel Street, Yiannis Tsapras, Joachim Wambsganss, Uffe Jørgensen, Valerio Bozza, P. Longã, Nuno Peixinho, Jesper Skottfelt, John Southworth, M. I. Andersen, M. Burgdorf, Giuseppe D'Ago, Daniel Evans, Tobias Hinse, Heidi Korhonen, Markus Rabus, Sohrab Rahvar

      Vol. 158 ( 5 )   2019.11

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

    We report the discovery of an exoplanet in microlensing event
    OGLE-2015-BLG-1649. The planet/host-star mass ratio is $q =7.2 \times 10^{-3}$
    and the projected separation normalized by the Einstein radius is $s = 0.9$.
    The upper limit of the lens flux is obtained from adaptive optics observations
    by IRCS/Subaru, which excludes the probability of a G-dwarf or more massive
    host star and helps to put a tighter constraint on the lens mass as well as
    commenting on the formation scenarios of giant planets orbiting low-mass stars.
    We conduct a Bayesian analysis including constraints on the lens flux to derive
    the probability distribution of the physical parameters of the lens system. We
    thereby find that the masses of the host star and planet are $M_{L} = 0.34 \pm
    0.19 M_{\odot}$ and $M_{p} = 2.5^{+1.5}_{-1.4} M_{Jup}$, respectively. The
    distance to the system is $D_{L} = 4.23^{+1.51}_{-1.64}$kpc. The projected
    star-planet separation is $a_{\perp} = 2.07^{+0.65}_{-0.77}$AU. The lens-source
    relative proper motion of the event is quite high, at $\sim 7.1 \, {\rm
    mas/yr}$. Therefore, we may be able to determine the lens physical parameters
    uniquely or place much stronger constraints on them by measuring the
    color-dependent centroid shift and/or the image elongation with additional high
    resolution imaging already a few years from now.

    DOI: 10.3847/1538-3881/ab4881

    Web of Science

    Scopus

    arXiv

  27. Multiple Populations of Extrasolar Gas Giants Reviewed

    Shohei Goda, Taro Matsuo

    ASTROPHYSICAL JOURNAL   Vol. 876 ( 1 )   2019.5

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    There are two planetary formation scenarios: core accretion and gravitational disk instability. Based on the fact that gaseous objects are preferentially observed around metal-rich host stars, most extrasolar gaseous objects discovered to date are thought to have been formed by core accretion. Here, we present 569 samples of gaseous planets and brown dwarfs found in 485 planetary systems that span three mass regimes with boundary values at 4 and 25 Jupiter-mass masses through performing cluster analyses of these samples regarding the host-star metallicity, after minimizing the impact of the selection effect of radial-velocity measurement on the cluster analysis. The larger mass is thought to be the upper mass limit of the objects that were formed during the planetary formation processes. In contrast, the lower mass limit appears to reflect the difference between planetary formation processes around early-type and G-type stars; disk instability plays a greater role in the planetary formation process around early-type stars than that around G-type stars. Populations with masses between 4 and 25 Jupiter masses that orbit early-type stars comprise planets formed not only via the core-accretion process but also via gravitational disk instability because the population preferentially orbits metal-poor stars or is independent of the host-star metallicity. Therefore, it is essential to have a hybrid scenario for the planetary formation of the diverse systems.

    DOI: 10.3847/1538-4357/ab0f9c

    Web of Science

    arXiv

  28. Multi-epoch Direct Imaging and Time-variable Scattered Light Morphology of the HD 163296 Protoplanetary Disk Reviewed

    Evan A. Rich, John P. Wisniewski, Thayne Currie, Misato Fukagawa, Carol A. Grady, Michael L. Sitko, Monika Pikhartova, Jun Hashimoto, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Joseph C. Carson, Jeffrey Chilcote, Ruobing Dong, Markus Feldt, Miwa Goto, Tyler Groff, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko S. Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Markus Janson, Nemanja Jovanovic, Ryo Kandori, Jeremy Kasdin, Gillian R. Knapp, Tomoyuki Kudo, Nobuhiko Kusakabe, Masayuki Kuzuhara, Jungmi Kwon, Julien Lozi, Frantz Martinache, Taro Matsuo, Satoshi Mayama, Michael W. McElwain, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martin, Takao Nakagawa, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Hiroshi Suto, Ray W. Russel, Ryuji Suzuki, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Edwin L. Turner, Taichi Uyama, Kevin R. Wagner, Makoto Watanabe, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura

    ASTROPHYSICAL JOURNAL   Vol. 875 ( 1 )   2019.4

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We present H-band polarized scattered light imagery and JHK high-contrast spectroscopy of the protoplanetary disk around HD 163296 observed with the High-Contrast Coronographic Imager for Adaptive Optics (HiCIAO) and Subaru Coronagraphic Extreme Adaptive Optics (SCExAO)/Coronagraphic High Angular Resolution Imaging Spectrograph (CHARTS) instruments at Subaru Observatory. The polarimetric imagery resolve a broken ring structure surrounding HD 163296 that peaks at a distance along the major axis of 0 ''.65 (66 au) and extends out to 0 ''.98 (100 au) along the major axis. Our 2011 H-band data exhibit clear axisymmetry, with the NW and SE side of the disk exhibiting similar intensities. Our data are clearly different from 2016 epoch H-band observations of the Very Large Telescope (VLT)/Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE), which found a strong 2.7 x asymmetry between the NW and SE side of the disk. Collectively, these results indicate the presence of time-variable, non-azimuthally symmetric illumination of the outer disk. While our SCExAO/CHARIS data are sensitive enough to recover the planet candidate identified from NIRC2 in the thermal infrared (IR), we fail to detect an object with JHK brightness nominally consistent with this object. This suggests that the candidate is either fainter in JHK bands than model predictions, possibly due to extinction from the disk or atmospheric dust/clouds, or that it is an artifact of the data set/data processing, such as a residual speckle or partially subtracted disk feature. Assuming standard hot-start evolutionary models and a system age of 5 Myr, we set new, direct mass limits for the inner (outer) Atacama Large Millimeter/submillimeter Array (ALMA)-predicted protoplanet candidate along the major (minor) disk axis of of 1.5 (2) M-J.

    DOI: 10.3847/1538-4357/ab0f3b

    Web of Science

    arXiv

  29. MOA-bin-29b : A Microlensing Gas Giant Planet Orbiting a Low-mass Host Star Reviewed

    Iona Kondo, Takahiro Sumi, David P. Bennett, Andrzej Udalski, Ian A. Bond, Nicholas J. Rattenbury, Valerio Bozza, Yuki Hirao, Daisuke Suzuki, Naoki Koshimoto, Masayuki Nagakane, Shota Miyazaki, Fumio Abe, Richard Barry, Aparna Bhattacharya, Martin Donachie, Akihiko Fukui, Hirosane Fujii, Yoshitaka Itow, Yuhei Kamei, Man Cheung Alex Li, Yutaka Matsubara, Taro Matsuo, Yasushi Muraki, Clément Ranc, Hiroshi Shibai, Haruno Suematsu, Denis J. Sullivan, Paul J. Tristram, Takeharu Yamakawa, Atsunori Yonehara, Przemek Mróz, Michał K. Szymański, Igor Soszyński, Krzysztof Ulaczyk

      Vol. 158 ( 6 )   2019

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

    We report the discovery of a gas giant planet orbiting a low-mass host star
    in the microlensing event MOA-bin-29 that occurred in 2006. We find five
    degenerate solutions with the planet/host-star mass ratio of $q \sim 10^{-2}$.
    The Einstein radius crossing time of all models are relatively short ($\sim
    4-7$ days), which indicates that the mass of host star is likely low. The
    measured lens-source proper motion is $5-9$ ${\rm mas}\ {\rm yr}^{-1}$
    depending on the models. Since only finite source effects are detected, we
    conduct a Bayesian analysis in order to obtain the posterior probability
    distribution of the lens physical properties. As a result, we find the lens
    system is likely to be a gas giant orbiting a brown dwarf or a very late
    M-dwarf in the Galactic bulge. The probability distributions of the physical
    parameters for the five degenerate models are consistent within the range of
    error. By combining these probability distributions, we conclude that the lens
    system is a gas giant with a mass of $M_{\rm p} = 0.63^{+1.13}_{-0.39}\ M_{\rm
    Jup}$ orbiting a brown dwarf with a mass of $M_{\rm h} = 0.06^{+0.11}_{-0.04}\
    M_\odot$ at a projected star-planet separation of $r_\perp =
    0.53^{+0.89}_{-0.18}\ {\rm au}$. The lens distance is $D_{\rm L} =
    6.89^{+1.19}_{-1.19}\ {\rm kpc}$, i.e., likely within the Galactic bulge.

    DOI: 10.3847/1538-3881/AB4E9E

    Web of Science

    Scopus

    arXiv

  30. A New Method for Calibration of Gain Variation in a Detector System Reviewed

    Shohei Goda, Taro Matsuo

    ASTRONOMICAL JOURNAL   Vol. 156 ( 6 )   2018.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    Transit spectroscopy of habitable planets orbiting late-type stars requires high relative spectrophotometric accuracy between wavelengths during transit/eclipse observation. The spectrophotometric signal is affected not only by image movement and deformation due to wavefront error but also by electrical variation in the detector system. These time-variation components, coupled to the transit signal, distort the measurements of atmospheric composition in transit spectroscopy. Here we propose a new concept for improvement of spectrophotometric accuracy through the calibration of the time-variation components in the detector system by developing densified pupil spectroscopy that provides multiple spectra of the star-planet system. Owing to a group of pixels exposed by the object light (i.e., science pixels), pixel-to-pixel variations can be smoothed out through an averaging operation; thus, only common time-variation components over the science pixels remain. In addition, considering that the detector plane is optically conjugated to the pupil plane, a pupil mask can completely block astronomical light coming into residual pixels. The common time-variation components are reconstructed with the residual pixels and reduced into a random term. Applying the densified pupil spectrograph with a mid-infrared detector system to a large space cryogenic telescope such as the Origins Space Telescope, we show that the system nearly achieves photon noise-limited performance and detects absorption features through transmission spectroscopy and secondary eclipse of terrestrial planets orbiting M-type stars at 10 pc with 60 transit observations. Thus, the proposed method contributes to the measurement of planetary habitability and biosignatures of the nearby transiting habitable candidates.

    DOI: 10.3847/1538-3881/aaeb29

    Web of Science

    arXiv

  31. A chemical survey of exoplanets with ARIEL Reviewed

    Giovanna Tinetti, Pierre Drossart, Paul Eccleston, Paul Hartogh, Astrid Heske, Jeremy Leconte, Giusi Micela, Marc Ollivier, Goran Pilbratt, Ludovic Puig, Diego Turrini, Bart Vandenbussche, Paulina Wolkenberg, Jean-Philippe Beaulieu, Lars A. Buchave, Martin Ferus, Matt Griffin, Manuel Guedel, Kay Justtanont, Pierre-Olivier Lagage, Pedro Machado, Giuseppe Malaguti, Michiel Min, Hans Ulrik Norgaard-Nielsen, Mirek Rataj, Tom Ray, Ignasi Ribas, Mark Swain, Robert Szabo, Stephanie Werner, Joanna Barstow, Matt Burleigh, James Cho, Vincent Coude du Foresto, Athena Coustenis, Leen Decin, Therese Encrenaz, Marina Galand, Michael Gillon, Ravit Helled, Juan Carlos Morales, Antonio Garcia Munoz, Andrea Moneti, Isabella Pagano, Enzo Pascale, Giuseppe Piccioni, David Pinfield, Subhajit Sarkar, Franck Selsis, Jonathan Tennyson, Amaury Triaud, Olivia Venot, Ingo Waldmann, David Waltham, Gillian Wright, Jerome Amiaux, Jean-Louis Augueres, Michel Berthe, Naidu Bezawada, Georgia Bishop, Neil Bowles, Deirdre Coffey, Josep Colome, Martin Crook, Pierre-Elie Crouzet, Vania Da Peppo, Isabel Escudero Sanz, Mauro Focardi, Martin Frericks, Tom Hunt, Ralf Kohley, Kevin Middleton, Gianluca Morgante, Roland Ottensamer, Emanuele Pace, Chris Pearson, Richard Stamper, Kate Symonds, Miriam Rengel, Etienne Renotte, Peter Ade, Laura Affer, Christophe Alard, Nicole Allard, Francesca Altieri, Yves Andre, Claudio Arena, Ioannis Argyriou, Alan Aylward, Cristian Baccani, Gaspar Bakos, Marek Banaszkiewicz, Mike Barlow, Virginie Batista, Giancarlo Bellucci, Serena Benatti, Pernelle Bernardi, Bruno Bezard, Maria Blecka, Emeline Bolmont, Bertrand Bonfond, Rosaria Bonito, Aldo S. Bonomo, John Robert Brucato, Allan Sacha Brun, Ian Bryson, Waldemar Bujwan, Sarah Casewell, Bejamin Charnay, Cesare Cecchi Pestellini, Guo Chen, Angela Ciaravella, Riccardo Claudi, Rodolphe Cledassou, Mario Damasso, Mario Damiano, Camilla Danielski, Pieter Deroo, Anna Maria Di Giorgio, Carsten Dominik, Vanessa Doublier, Simon Doyle, Rene Doyon, Benjamin Drummond, Bastien Duong, Stephen Eales, Billy Edwards, Maria Farina, Ettore Flaccomio, Leigh Fletcher, Francois Forget, Steve Fossey, Markus Fraenz, Yuka Fujii, Alvaro Garcia-Piquer, Walter Gear, Herve Geoffray, Jean Claude Gerard, Lluis Gesa, H. Gomez, Rafal Graczyk, Caitlin Griffith, Denis Grodent, Mario Giuseppe Guarcello, Jacques Gustin, Keiko Hamano, Peter Hargrave, Yann Hello, Kevin Heng, Enrique Herrero, Allan Hornstrup, Benoit Hubert, Shigeru Ida, Masahiro Ikoma, Nicolas Iro, Patrick Irwin, Christopher Jarchow, Jean Jaubert, Hugh Jones, Queyrel Julien, Shingo Kameda, Franz Kerschbaum, Pierre Kervella, Tommi Koskinen, Matthijs Krijger, Norbert Krupp, Marina Lafarga, Federico Landini, Emanuel Lellouch, Giuseppe Leto, A. Luntzer, Theresa Rank-Luftinger, Antonio Maggio, Jesus Maldonado, Jean-Pierre Maillard, Urs Mall, Jean-Baptiste Marquette, Stephane Mathis, Pierre Maxted, Taro Matsuo, Alexander Medvedev, Yamila Miguel, Vincent Minier, Giuseppe Morello, Alessandro Mura, Norio Narita, Valerio Nascimbeni, N. Nguyen Tong, Vladimiro Noce, Fabrizio Oliva, Enric Palle, Paul Palmer, Maurizio Pancrazzi, Andreas Papageorgiou, Vivien Parmentier, Manuel Perger, Antonino Petralia, Stefano Pezzuto, Ray Pierrehumbert, Ignazio Pillitteri, Giampaolo Piotto, Giampaolo Pisano, Loredana Prisinzano, Aikaterini Radioti, Jean-Michel Reess, Ladislav Rezac, Marco Rocchetto, Albert Rosich, Nicoletta Sanna, Alexandre Santerne, Giorgio Savini, Gaetano Scandariato, Bruno Sicardy, Carles Sierra, Giuseppe Sindoni, Konrad Skup, Ignas Snellen, Mateusz Sobiecki, Lauriane Soret, Alessandro Sozzetti, A. Stiepen, Antoine Strugarek, Jake Taylor, William Taylor, Luca Terenzi, Marcell Tessenyi, Angelos Tsiaras, C. Tucker, Diana Valencia, Gautam Vasisht, Allona Vazan, Francesc Vilardell, Sabrine Vinatier, Serena Viti, Rens Waters, Piotr Wawer, Anna Wawrzaszek, Anthony Whitworth, Yuk L. Yung, Sergey N. Yurchenko, Maria Rosa Zapatero Osorio, Robert Zellem, Tiziano Zingales, Frans Zwart

    EXPERIMENTAL ASTRONOMY   Vol. 46 ( 1 ) page: 135 - 209   2018.11

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

    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet's birth, and evolution. ARIEL was conceived to observe a large number (1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25-7.8m spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10-100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed - using conservative estimates of mission performance and a full model of all significant noise sources in the measurement - using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL - in line with the stated mission objectives - will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.

    DOI: 10.1007/s10686-018-9598-x

    Web of Science

  32. MOA-2015-BLG-337: A Planetary System with a Low-mass Brown Dwarf/Planetary Boundary Host, or a Brown Dwarf Binary Reviewed

    Miyazaki S., Sumi T., Bennett D.P., Gould A., Udalski A., Bond I.A., Koshimoto N., Nagakane M., Rattenbury N., Abe F., Bhattacharya A., Barry R., Donachie M., Fukui A., Hirao Y., Itow Y., Kawasaki K., Li M.C.A., Ling C.H., Matsubara Y., Matsuo T., Muraki Y., Ohnishi K., Ranc C., Saito T., Sharan A., Shibai H., Suematsu H., Suzuki D., Sullivan D.J., Tristram P.J., Yamada T., Yonehara A., KozŁowski S., Mróz P., Pawlak M., Poleski R., Pietrukowicz P., Skowron J., Soszyński I., Szymański M.K., Ulaczyk K., Albrow M.D., Chung S.J., Han C., Jung Y.K., Hwang K.H., Ryu Y.H., Shin I.G., Shvartzvald Y., Yee J.C., Zang W., Zhu W., Cha S.M., Kim D.J., Kim H.W., Kim S.L., Lee C.U., Lee D.J., Lee Y., Park B.G., Pogge R.W.

    Astronomical Journal   Vol. 156 ( 3 )   2018.9

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Astronomical Journal  

    We report on the discovery and analysis of the short-timescale binary-lens microlensing event, MOA-2015-BLG-337. The lens system could be a planetary system with a very low-mass host, around the brown dwarf (BD)/planetary-mass boundary, or a BD binary. We found two competing models that explain the observed light curves with companion/host mass ratios of q ∼ 0.01 and ∼0.17, respectively. A significant finite source effect in the best-fit planetary model (q ∼ 0.01) reveals a small angular Einstein radius of θ E ≃ 0.03 mas, which favors a low-mass lens. We obtain the posterior probability distribution of the lens properties from a Bayesian analysis. The results for the planetary models strongly depend on a power-law index in planetary-mass regime, pl, in the assumed mass function. In summary, there are two solutions of the lens system: (1) a BD/planetary-mass boundary object orbited by a super-Neptune (the planetary model with α pl = 0.49) and (2) a BD binary (the binary model). If the planetary models are correct, this system can be one of a new class of planetary system, having a low host mass and also a planetary-mass ratio (q < 0.03) between the companion and its host. The discovery of the event is important for the study of planetary formation in very low-mass objects. In addition, it is important to consider all viable solutions in these kinds of ambiguous events in order for the future comprehensive statistical analyses of planetary/binary microlensing events.

    DOI: 10.3847/1538-3881/aad5ee

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    Scopus

  33. Subaru/HiCIAO HKs Imaging of LKHa 330: Multi-band Detection of the Gap and Spiral-like Structures Reviewed

    Taichi Uyama, Jun Hashimoto, Takayuki Muto, Eiji Akiyama, Ruobing Dong, Jerome de Leon, Itsuki Sakon, Tomoyuki Kudo, Nobuhiko Kusakabe, Masayuki Kuzuhara, Mickael Bonnefoy, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Joseph C. Carson, Thayne Currie, Sebastian Egner, Markus Feldt, Jeffrey Fung, Miwa Goto, Carol A. Grady, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko S. Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Markus Janson, Ryo Kandori, Gillian R. Knapp, Jungmi Kwon, Taro Matsuo, Satoshi Mayama, Michael W. Mcelwain, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martin, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Michael L. Sitko, Takuya Suenaga, Hiroshi Suto, Ryuji Suzuki, Yasuhiro H. Takahashi, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Edwin L. Turner, Makoto Watanabe, John Wisniewski, Toru Yamada, Yi Yang, Hideki Takami, Tomonori Usuda, Motohide Tamura

    ASTRONOMICAL JOURNAL   Vol. 156 ( 2 )   2018.8

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We present H- and K-s-bands observations of the LkH alpha 330 disk with a multi-band detection of the large gap and spiral-like structures. The morphology of the outer disk (r similar to 0."3) at PA = 0 degrees-45 degrees and PA degrees = 180-290 degrees is likely density wave-induced spirals, and comparison between our observational results and simulations suggests a planet formation. We have also investigated the azimuthal profiles at the ring and the outer-disk regions as well as radial profiles in the directions of the spiral-like structures and semimajor axis. Azimuthal analysis shows a large variety in wavelength and implies that the disk has non-axisymmetric dust distributions. The radial profiles in the major-axis direction (PA = 271 degrees) suggest that the outer region (r >= 0."25) may be influenced by shadows of the inner region of the disk. The spiral-like directions (PA = 10 degrees and 230 degrees) show different radial profiles, which suggests that the surfaces of the spiral-like structures are highly flared and/or have different dust properties. Finally, a color map of the disk shows a lack of an outer eastern region in the H-band disk, which may hint at the presence of an inner object that casts a directional shadow onto the disk.

    DOI: 10.3847/1538-3881/aacbd1

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    arXiv

  34. High-contrast Polarimetry Observation of the T Tau Circumstellar Environment Reviewed

    Yi Yang, Satoshi Mayama, Saeko S. Hayashi, Jun Hashimoto, Roman Rafikov, Eiji Akiyama, Thayne Currie, Markus Janson, Munetake Momose, Takao Nakagawa, Daehyeon Oh, Tomoyuki Kudo, Nobuhiko Kusakabe, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Joseph C. Carson, Sebastian Egner, Markus Feldt, Miwa Goto, Carol A. Grady, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Ryo Kandori, Gillian R. Knapp, Jungmi Kwon, Masayuki Kuzuhara, Taro Matsuo, Michael W. Mcelwain, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-martin, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Takuya Suenaga, Hiroshi Suto, Ryuji Suzuki, Yasuhiro H. Takahashi, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Edwin L. Turner, Makoto Watanabe, John Wisniewski, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura

    ASTROPHYSICAL JOURNAL   Vol. 861 ( 2 )   2018.7

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We conducted high-contrast polarimetry observations of T Tau in the H-band, using the High Contrast Instrument for the Subaru Next Generation Adaptive Optics instrument mounted on the Subaru Telescope, revealing structures as near as 0 1 from the stars T Tau N and T Tau S. The whole T Tau system is found to be surrounded by nebulalike envelopes, and several outflow-related structures are detected in these envelopes. We analyzed the detailed polarization patterns of the circumstellar structures near each component of this triple young star system and determined constraints on the circumstellar disks and outflow structures. We suggest that the nearly face-on circumstellar disk of T Tau N is no larger than 0.''8, or 117 au, in the northwest, based on the existence of a hole in this direction, and no larger than 0.''27, or 40 au, in the south. A new structure, "N5," extends to about 0.''42, or 59 au, southwest of the star, and is believed to be part of the disk. We suggest that T Tau S is surrounded by a highly inclined circumbinary disk with a radius of about 0.''3, or 44 au, with a position angle of about 30 degrees, that is misaligned with the orbit of the T Tau S binary. After analyzing the positions and polarization vector patterns of the outflow-related structures, we suggest that T Tau S should trigger the well-known E-W outflow, and is also likely to be responsible for a southwest precessing outflow "coil" and a possible south outflow.

    DOI: 10.3847/1538-4357/aac6c8

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    arXiv

  35. The infrared Doppler (IRD) instrument for the Subaru telescope: instrument description and commissioning results Reviewed

    Takayuki Kotani, Motohide Tamura, Jun Nishikawa, Akitoshi Ueda, Masayuki Kuzuhara, Masashi Omiya, Jun Hashimoto, Masato Ishizuka, Teruyuki Hirano, Hiroshi Suto, Takashi Kurokawa, Tsukasa Kokubo, Takahiro Mori, Yosuke Tanaka, Ken Kashiwagi, Mihoko Konishi, Tomoyuki Kudo, Bun'ei Sato, Shane Jacobson, Klaus W. Hodapp, Donald B. Hall, Wako Aoki, Tomonori Usuda, Shogo Nishiyama, Tadashi Nakajima, Yuji Ikeda, Tomoyasu Yamamuro, Jun-Ichi Morino, Haruka Baba, Ko Hosokawa, Hiroyuki Tako Ishikawa, Norio Narita, Eiichiro Kokubo, Yutaka Hayano, Hideyuki Izumiura, Eiji Kambe, Nobuhiko Kusakabe, Jungmi Kwon, Masahiro Ikoma, Yasunori Hori, Hidenori Genda, Akihiko Fukui, Yuka Fujii, Hajime Kawahara, Olivier Guyon, Nemanja Jovanovi, Hiroki Harakawa, Masahiko Hayashi, Masahide Hidai, Masahiro Machida, Taro Matsuo, Tetsuya Nagata, Masahiro Ogihara, Hideki Takami, Naruhisa Takato, Hiroshi Terada, Daehyeon Oh

    GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY VII   Vol. 10702   2018

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:SPIE-INT SOC OPTICAL ENGINEERING  

    The Infrared Doppler (IRD) instrument is a fiber-fed high-resolution NIR spectrometer for the Subaru telescope covering the Y,J,H-bands simultaneously with a maximum spectral resolution of 70,000. The main purpose of IRD is a search for Earth-mass planets around nearby M-dwarfs by precise radial velocity measurements, as well as a spectroscopic characterization of exoplanet atmospheres. We report the current status of the instrument, which is undergoing commissioning at the Subaru Telescope, and the first light observation successfully done in August 2017. The general description of the instrument will be given including spectrometer optics, fiber injection system, cryogenic system, scrambler, and laser frequency comb. A large strategic survey mainly focused on late-type M-dwarfs is planned to start from 2019.

    DOI: 10.1117/12.2311836

    Web of Science

  36. Mid-Infrared Imager, Spectrometer, Coronagraph (MISC) for the Origins Space Telescope (OST) Reviewed

    Itsuki Sakon, Thomas L. Roellig, Kimberly Ennico-Smith, Taro Matsuo, Yuji Ikeda, Tomoyasu Yamamuro, Naofumi Fujishiro, Keigo Enyag, Aoi Takahashi, Takehiko Wada, Olivier Guyon, Takayuki Kotani, Jun Nishikawa, Naoshi Murakami, Yuki Sarugaku, Denis Burgarella

    SPACE TELESCOPES AND INSTRUMENTATION 2018: OPTICAL, INFRARED, AND MILLIMETER WAVE   Vol. 10698   2018

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:SPIE-INT SOC OPTICAL ENGINEERING  

    The Mid-infrared Imager, Spectrometer, Coronagraph (MISC) is one of the instruments studied both for the Origins Space Telescope (OST) Mission Concept 1 and 2. The highest ever spectro-photometric stability achieved by MISC transit spectrometer module (MISC TRA) enables to detect bio-signatures (e.g., ozone, water, and methane) in habitable worlds in both primary and secondary transits of exoplanets and makes the OST a powerful tool to bring a revolutionary progress in exoplanet sciences. Combined with the spectroscopic capability in the FIR provided by other OST instruments, the MISC widens the wavelength coverage of OST down to 4 mu m, which makes the OST a powerful tool to diagnose the physical and chemical condition of the ISM using dust features, molecules lines and atomic and ionic lines. The MISC also provides the OST with a focal plane guiding function for the other OST science instruments as well as its own use.

    DOI: 10.1117/12.2314177

    Web of Science

  37. A highly stable spectrophotometric capability for the Origins Space Telescope (OST) Mid-infrared Imager, Spectrometer, Coronagraph (MISC) Reviewed

    Taro Matsuo, Thomas Greene, Thomas L. Roellig, Robert E. McMurray, Roy R. Johnson, Ali Kashani, Shohei Goda, Masayuki Ido, Satoshi Ito, Takahiro Tsuboi, Tomoyasu Yamamuro, Yuji Ikeda, Hiroshi Shibai, Takahiro Sumi, Itsuki Sakon, Kimberly Ennico-Smith

    SPACE TELESCOPES AND INSTRUMENTATION 2018: OPTICAL, INFRARED, AND MILLIMETER WAVE   Vol. 10698   2018

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:SPIE-INT SOC OPTICAL ENGINEERING  

    This paper describes the transit spectrograph designed for the Origins Space Telescope mid-infrared imager, spectrometer, coronagraph (MISC) and its performance derived through analytical formulation and numerical simulation. The transit spectrograph is designed based on a densified pupil spectroscopy design that forms multiple independent spectra on the detector plane and minimizes the systematic noise in the optical system. This design can also block any thermal light incoming into pixels around the transit spectra. The gain fluctuations occurring in the detector and readout electronics are accurately corrected by use of a number of blanked-off pixels. We found that the transit spectrograph for the OST concept 1 with a diameter of 9.3m potentially achieves the photon-noise-limited performance and allows detection of biosignature gases through transmission spectroscopy of transiting planets orbiting late- and middle-M type stars at 10 pc with 60 transit observations.

    DOI: 10.1117/12.2311896

    Web of Science

  38. The fundamental stellar parameters of FGK stars in the SEEDS survey Norman, OK 73071, USA Reviewed

    Evan A. Rich, John P. Wisniewski, Michael W. McElwain, Jun Hashimoto, Tomoyuki Kudo, Nobuhiko Kusakabe, Yoshiko K. Okamoto, Lyu Abe, Eiji Akiyama, Wolfgang Brandner, Timothy D. Brandt, Phillip Cargile, Joseph C. Carson, Thayne M. Currie, Sebastian Egner, Markus Feldt, Misato Fukagawa, Miwa Goto, Carol A. Grady, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko S. Hayashi, Leslie Hebb, Krzysztof G. Helminiak, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Markus Janson, Ryo Kandori, Gillian R. Knapp, Masayuki Kuzuhara, Jungmi Kwon, Taro Matsuo, Satoshi Mayama, Shoken Miyama, Munetake Momose, Jun-Ichi Morino, Amaya Moro-Martin, Takao Nakagawa, Tetsuo Nishimura, Daehyeon Oh, Tae-Soo Pyo, Joshua Schlieder, Eugene Serabyn, Michael L. Sitko, Takuya Suenaga, Hiroshi Suto, Ryuji Suzuki, Yasuhiro H. Takahashi, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Daigo Tomono, Edwin L. Turner, Makoto Watanabe, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura

    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY   Vol. 472 ( 2 ) page: 1736 - 1752   2017.12

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:OXFORD UNIV PRESS  

    Large exoplanet surveys have successfully detected thousands of exoplanets to-date. Utilizing these detections and non-detections to constrain our understanding of the formation and evolution of planetary systems also requires a detailed understanding of the basic properties of their host stars. We have determined the basic stellar properties of F, K and G stars in the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) survey from Echelle spectra taken at the Apache Point Observatory's 3.5m telescope. Using ROBOSPECT to extract line equivalent widths and TemperatureGravity microtrubulentVelocity ITerations to calculate the fundamental parameters, we have computed T-eff, log(g), v(t), [Fe/H], chromospheric activity and the age for our sample. Our methodology was calibrated against previously published results for a portion of our sample. The distribution of [Fe/H] in our sample is consistent with that typical of the Solar neighbourhood. Additionally, we find the ages of most of our sample are < 500 Myr, but note that we cannot determine robust ages from significantly older stars via chromospheric activity age indicators. The futuremeta-analysis of the frequency ofwide stellar and sub-stellar companions imaged via the SEEDS survey will utilize our results to constrain the occurrence of detected comoving companions with the properties of their host stars.

    DOI: 10.1093/mnras/stx2051

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    arXiv

  39. Pupil Masks for Spectrophotometry of Transiting Exoplanets Reviewed

    Satoshi Itoh, Taro Matsuo, Shohei Goda, Hiroshi Shibai, Takahiro Sumi

    ASTRONOMICAL JOURNAL   Vol. 154 ( 3 )   2017.9

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    Spectrophotometric stability, which is crucial in the spectral characterization of transiting exoplanets, is affected by photometric variations arising from field-stop loss in space telescopes with pointing jitter or primary mirror deformation. This paper focuses on a new method for removing slit-loss or field-stop-loss photometric variation through the use of a pupil mask. Two types of pupil function are introduced: the first uses conventional (e.g., Gaussian or hyper-Gaussian) apodizing patterns; whereas the second, which we call a block-shaped mask, employs a new type of pupil mask designed for high photometric stability. A methodology for the optimization of a pupil mask for transit observations is also developed. The block-shaped mask can achieve a photometric stability of 10(-5) for a nearly arbitrary field-stop radius when the pointing jitter is smaller than approximately 0.7 lambda/D and a photometric stability of 10(-6) at a pointing jitter smaller than approximately 0.5 lambda/D. The impact of optical aberrations and mask imperfections upon mask performance is also discussed.

    DOI: 10.3847/1538-3881/aa8304

    Web of Science

    arXiv

  40. OGLE-2013-BLG-1761Lb: A Massive Planet around an M/K Dwarf Reviewed

    Y. Hirao, A. Udalski, T. Sumi, D. P. Bennett, N. Koshimoto, I. A. Bond, N. J. Rattenbury, D. Suzuki, F. Abe, Y. Asakura, R. K. Barry, A. Bhattacharya, M. Donachie, P. Evans, A. Fukui, Y. Itow, M. C.A. Li, C. H. Ling, K. Masuda, Y. Matsubara, T. Matsuo, Y. Muraki, M. Nagakane, K. Ohnishi, C. Ranc, To Saito, A. Sharan, H. Shibai, D. J. Sullivan, P. J. Tristram, T. Yamada, T. Yamada, A. Yonehara, R. Poleski, J. Skowron, P. Mróz, M. K. Szymański, S. Kozłowski, P. Pietrukowicz, I. Soszyński, Wyrzykowski, K. Ulaczyk

    Astronomical Journal   Vol. 154 ( 1 )   2017.7

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Institute of Physics Publishing  

    We report the discovery and the analysis of the planetary microlensing event, OGLE-2013-BLG-1761. There are some degenerate solutions in this event because the planetary anomaly is only sparsely sampled. However, the detailed light-curve analysis ruled out all stellar binary models and shows the lens to be a planetary system. There is the so-called close/wide degeneracy in the solutions with the planet/host mass ratio of q ∼ (7.0 ±2.0) ×10-3 and q ∼ (8.1 ±2.6) ×10-3 with the projected separation in Einstein radius units of s = 0.95 (close) and s = 1.18 (wide), respectively. The microlens parallax effect is not detected, but the finite source effect is detected. Our Bayesian analysis indicates that the lens system is located DL = 6.9+1.0-1.2. away from us and the host star is an M/K dwarf with a mass of ML = 0.33+0.32-0.19 M⊙ orbited by a super-Jupiter mass planet with a mass of mp = 2.7+2.5-1.5 MJup at the projected separation of a⊥ = 1.8+0.5-0.5 au. The preference of the large lens distance in the Bayesian analysis is due to the relatively large observed source star radius. The distance and other physical parameters may be constrained by the future high-resolution imaging by large ground telescopes or HST. If the estimated lens distance is correct, then this planet provides another sample for testing the claimed deficit of planets in the Galactic bulge.

    DOI: 10.3847/1538-3881/aa73da

    Web of Science

    Scopus

  41. MOA-2012-BLG-505Lb: A Super-Earth-mass Planet That Probably Resides in the Galactic Bulge Reviewed

    M. Nagakane, T. Sumi, N. Koshimoto, D. P. Bennett, I. A. Bond, N. Rattenbury, D. Suzuki, F. Abe, Y. Asakura, R. Barry, A. Bhattacharya, M. Donachie, A. Fukui, Y. Hirao, Y. Itow, M. C.A. Li, C. H. Ling, K. Masuda, Y. Matsubara, T. Matsuo, Y. Muraki, K. Ohnishi, C. Ranc, To. Saito, A. Sharan, H. Shibai, D. J. Sullivan, P. J. Tristram, T. Yamada, A. Yonehara

    Astronomical Journal   Vol. 154 ( 1 )   2017.7

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Institute of Physics Publishing  

    We report the discovery of a super-Earth-mass planet in the microlensing event MOA-2012-BLG-505. This event has the second shortest event timescale of t E = 10 ± 1 days where the observed data show evidence of a planetary companion. Our 15 minute high cadence survey observation schedule revealed the short subtle planetary signature. The system shows the well known close/wide degeneracy. The planet/host-star mass ratio is q = 2.1 times
    10-4 and the projected separation normalized by the Einstein radius is s = 1.1 or 0.9 for the wide and close solutions, respectively. We estimate the physical parameters of the system by using a Bayesian analysis and find that the lens consists of a super-Earth with a mass of 6.7 10.7-3.6 M⊕ orbiting around a brown dwarf or late-M-dwarf host with a mass of 0.10 +0.16-0.05 M⊙ with a projected star-planet separation of 0.9+0.30.2. The system is at a distance of 7.2 ± 1.1 kpc, i.e., it is likely to be in the Galactic bulge. The small angular Einstein radius (θ E = 0.12 ± 0.02 mas) and short event timescale are typical for a low-mass lens in the Galactic bulge. Such low-mass planetary systems in the Bulge are rare because the detection efficiency of planets in short microlensing events is relatively low. This discovery may suggest that such low-mass planetary systems are abundant in the Bulge and currently on-going high cadence survey programs will detect more such events and may reveal an abundance of such planetary systems.

    DOI: 10.3847/1538-3881/aa74b2

    Web of Science

    Scopus

    arXiv

  42. MOA-2016-BLG-227Lb: A Massive Planet Characterized by Combining Light-curve Analysis and Keck AO Imaging Reviewed

    N. Koshimoto, Y. Shvartzvald, D. P. Bennett, M. T. Penny, M. Hundertmark, I. A. Bond, W. C. Zang, C. B. Henderson, D. Suzuki, N. J. Rattenbury, T. Sumi, F. Abe, Y. Asakura, A. Bhattacharya, M. Donachie, P. Evans, A. Fukui, Y. Hirao, Y. Itow, M. C.A. Li, C. H. Ling, K. Masuda, Y. Matsubara, T. Matsuo, Y. Muraki, M. Nagakane, K. Ohnishi, C. Ranc, To. Saito, A. Sharan, H. Shibai, D. J. Sullivan, P. J. Tristram, T. Yamada, T. Yamada, A. Yonehara, C. R. Gelino, C. Beichman, J. P. Beaulieu, J. B. Marquette, V. Batista, M. Friedmann, N. Hallakoun, S. Kaspi, D. Maoz, G. Bryden, S. Calchi Novati, S. B. Howell, T. S. Wang, S. Mao, P. Fouqué, H. Korhonen, U. G. Jørgensen, R. Street, Y. Tsapras, M. Dominik, E. Kerins, A. Cassan, C. Snodgrass, E. Bachelet, V. Bozza, D. M. Bramich

    Astronomical Journal   Vol. 154 ( 1 )   2017.7

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Institute of Physics Publishing  

    We report the discovery of a microlensing planet - MOA-2016-BLG-227Lb - with a large planet/host mass ratio of q ≃ 9 ×10-3. This event was located near the K2 Campaign 9 field that was observed by a large number of telescopes. As a result, the event was in the microlensing survey area of a number of these telescopes, and this enabled good coverage of the planetary light-curve signal. High angular resolution adaptive optics images from the Keck telescope reveal excess flux at the position of the source above the flux of the source star, as indicated by the light-curve model. This excess flux could be due to the lens star, but it could also be due to a companion to the source or lens star, or even an unrelated star. We consider all these possibilities in a Bayesian analysis in the context of a standard Galactic model. Our analysis indicates that it is unlikely that a large fraction of the excess flux comes from the lens, unless solar-type stars are much more likely to host planets of this mass ratio than lower mass stars. We recommend that a method similar to the one developed in this paper be used for other events with high angular resolution follow-up observations when the follow-up observations are insufficient to measure the lens-source relative proper motion.

    DOI: 10.3847/1538-3881/aa72e0

    Web of Science

    Scopus

    arXiv

  43. The SEEDS High-Contrast Imaging Survey of Exoplanets Around Young Stellar Objects Reviewed

    Taichi Uyama, Jun Hashimoto, Masayuki Kuzuhara, Satoshi Mayama, Eiji Akiyama, Thayne Currie, John Livingston, Tomoyuki Kudo, Nobuhiko Kusakabe, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Joseph C. Carson, Sebastian Egner, Markus Feldt, Miwa Goto, Carol A. Grady, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko S. Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Markus Janson, Ryo Kandori, Gillian R. Knapp, Jungmi Kwon, Taro Matsuo, Michael W. Mcelwain, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martin, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Takuya Suenaga, Hiroshi Suto, Ryuji Suzuki, Yasuhiro H. Takahashi, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Edwin L. Turner, Makoto Watanabe, John Wisniewski, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura

    ASTRONOMICAL JOURNAL   Vol. 153 ( 3 )   2017.3

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    We present high-contrast observations of 68 young stellar objects (YSOs) that have been explored as part of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS) survey on the Subaru telescope. Our targets are very young (<10Myr) stars, which often harbor protoplanetary disks where planets may be forming. We achieve a typical contrast of similar to 10(-4)-10(-5.5) at an angular distance of 1" from the central star, corresponding to typical mass sensitivities (assuming hot-start evolutionary models) of similar to 10 M-J at 70 au and similar to 6 M-J at 140 au. We detected a new stellar companion to HIP 79462 and confirmed the substellar objects GQ Lup b and ROXs 42B b. An additional six companion candidates await follow-up observations to check for common proper motion. Our SEEDS YSO observations probe the population of planets and brown dwarfs at the very youngest ages; these may be compared to the results of surveys targeting somewhat older stars. Our sample and the associated observational results will help enable detailed statistical analyses of giant planet formation.

    DOI: 10.3847/1538-3881/153/3/106

    Web of Science

    arXiv

  44. Radial decoupling of small and large dust grains in the transitional disk RX J1615.3-3255 Reviewed

    Robin Kooistra, Inga Kamp, Misato Fukagawa, Franois Menard, Munetake Momose, Takashi Tsukagoshi, Tomoyuki Kudo, Nobuhiko Kusakabe, Jun Hashimoto, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Joseph C. Carson, Sebastian E. Egner, Markus Feldt, Miwa Goto, Carol A. Grady, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Saeko S. Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Markus Janson, Ryo Kandori, Gillian R. Knapp, Masayuki Kuzuhara, Jungmi Kwon, Taro Matsuo, Michael W. McElwain, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martin, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Takuya Suenaga, Hiroshi Suto, Ryuji Suzuki, Yasuhiro H. Takahashi, Michihiro Takami, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Daigo Tomono, Edwin L. Turner, Makoto Watanabe, John Wisniewski, Toru Yamada, Hideki Takami, Tomonori Usuda, Motohide Tamura, Thayne Currie, Eiji Akiyama, Satoshi Mayama, Katherine B. Follette, Takao Nakagawa

    ASTRONOMY & ASTROPHYSICS   Vol. 597   2017.1

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

    We present H-band (1.6 mu m) scattered light observations of the transitional disk RX J1615.3-3255, located in the similar to 1 Myr old Lupus association. From a polarized intensity image, taken with the HiCIAO instrument of the Subaru Telescope, we deduce the position angle and the inclination angle of the disk. The disk is found to extend out to 68 +/- 12 AU in scattered light and no clear structure is observed. Our inner working angle of 24 AU does not allow us to detect a central decrease in intensity similar to that seen at 30 AU in the 880 mu m continuum observations. We compare the observations with multiple disk models based on the spectral energy distribution (SED) and submm interferometry and find that an inner rim of the outer disk at 30 AU containing small silicate grains produces a polarized intensity signal which is an order of magnitude larger than observed. We show that a model in which the small dust grains extend smoothly into the cavity found for large grains is closer to the actual H-band observations. A comparison of models with di ff erent dust size distributions suggests that the dust in the disk might have undergone significant processing compared to the interstellar medium.

    DOI: 10.1051/0004-6361/201628696

    Web of Science

    Scopus

    arXiv

  45. OGLE-2012-BLG-0950Lb: The FIRST PLANET MASS MEASUREMENT from only MICROLENS PARALLAX and LENS FLUX Reviewed

    N. Koshimoto, A. Udalski, J. P. Beaulieu, T. Sumi, D. P. Bennett, I. A. Bond, N. Rattenbury, A. Fukui, V. Batista, J. B. Marquette, S. Brillant, F. Abe, Y. Asakura, A. Bhattacharya, M. Donachie, M. Freeman, Y. Hirao, Y. Itow, M. C.A. Li, C. H. Ling, K. Masuda, Y. Matsubara, T. Matsuo, Y. Muraki, M. Nagakane, K. Ohnishi, H. Oyokawa, To. Saito, A. Sharan, H. Shibai, D. J. Sullivan, D. Suzuki, P. J. Tristram, A. Yonehara, S. Kozłowski, P. Pietrukowicz, R. Poleski, J. Skowron, I. Soszyński, M. K. Szymański, K. Ulaczyk, Ł. Wyrzykowski

    Astronomical Journal   Vol. 153 ( 1 )   2017.1

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Institute of Physics Publishing  

    We report the discovery of a microlensing planet OGLE-2012-BLG-0950Lb with a planet/host mass ratio of q ≃ 2 10-4. A long term distortion detected in both MOA and OGLE light curve can be explained by the microlens parallax due to the Earths orbital motion around the Sun. Although the finite source effect is not detected, we obtain the lens flux by the high resolution Keck AO observation. Combining the microlens parallax and the lens flux reveal the nature of the lens: a planet with mass of = Mp=35+17-9is orbiting around an M-dwarf with mass of =Mhost=0.56+0.12-0.16Ṁwith a planet-host projected separation of = r⊥=2.7+0.6-0.7 au located at = - DL 3.0+ 0.8-1.1kpc from us. This is the first mass measurement from only microlens parallax and the lens flux without the finite source effect. In the coming space observation-era with Spitzer, K2, Euclid, and WFIRST, we expect many such events for which we will not be able to measure any finite source effect. This work demonstrates an ability of mass measurements in such events.

    DOI: 10.3847/1538-3881/153/1/1

    Web of Science

    Scopus

  46. NEAR-INFRARED IMAGING POLARIMETRY OF INNER REGION OF GG TAU A DISK Reviewed

    Yi Yang, Jun Hashimoto, Saeko S. Hayashi, Motohide Tamura, Satoshi Mayama, Roman Rafikov, Eiji Akiyama, Joseph C. Carson, Markus Janson, Jungmi Kwon, Jerome De Leon, Daehyeon Oh, Michihiro Takami, Ya-Wen Tang, Tomoyuki Kudo, Nobuhiko Kusakabe, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Sebastian Egner, Markus Feldt, Miwa Goto, Carol A. Grady, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Ryo Kandori, Gillian R. Knapp, Masayuki Kuzuhara, Taro Matsuo, Michael W. Mcelwain, Shoken Miyama, Jun-Ichi Morino, Amaya Moro-Martin, Tetsuo Nishimura, Tae-Soo Pyo, Eugene Serabyn, Takuya Suenaga, Hiroshi Suto, Ryuji Suzuki, Yasuhiro H. Takahashi, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Edwin L. Turner, Makoto Watanabe, John Wisniewski, Toru Yamada, Hideki Takami, Tomonori Usuda

    ASTRONOMICAL JOURNAL   Vol. 153 ( 1 )   2017.1

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    Language:English   Publishing type:Research paper (scientific journal)   Publisher:IOP PUBLISHING LTD  

    By performing non-masked polarization imaging with Subaru/HiCIAO, polarized scattered light from the inner region of the disk around the GG Tau A system was successfully detected in the H band, with a spatial resolution of approximately 0 07, revealing the complicated inner disk structures around this young binary. This paper reports the observation of an arc-like structure to the north of GG Tau Ab, and part of a circumstellar structure that is noticeable around GG Tau Aa, extending to a distance of approximately 28 au from the primary star. The speckle noise around GG Tau Ab constrains its disk radius to < 13 au. Based on the size of the circumbinary ring and the circumstellar disk around GG Tau Aa, the semimajor axis of the binary's orbit is likely to be 62 au. A comparison of the present observations with previous Atacama Large Millimeter Array and near-infrared H-2 emission observations suggests that the north arc could be part of a large streamer flowing from the circumbinary ring to sustain the circumstellar disks. According to the previous studies, the circumstellar disk around GG Tau Aa has enough mass and can sustain itself for a duration sufficient for planet formation; thus, our study indicates that planets can form within close (separation. 100 au) young binary systems.

    DOI: 10.3847/1538-3881/153/1/7

    Web of Science

    arXiv

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Books 1

  1. 宇宙から考えてみる「生命とは何か?」入門

    松尾 太郎

    河出書房新社  2023  ( ISBN:9784309617572

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    Language:Japanese

    CiNii Books

MISC 2

  1. SUBARU Near-Infrared Imaging Polarimetry of Misaligned Disks Around The SR24 Hierarchical Triple System

    Satoshi Mayama, Sebastián Pérez, Nobuhiko Kusakabe, Takayuki Muto, Takashi Tsukagoshi, Michael L. Sitko, Michihiro Takami, Jun Hashimoto, Ruobing Dong, Jungmi Kwon, Saeko S. Hayashi, Tomoyuki Kudo, Masayuki Kuzuhara, Kate B. Follette, Misato Fukagawa, Munetake Momose, Daehyeon Oh, Jerome De Leon, Eiji Akiyama, John P. Wisniewski, Yi Yang, Lyu Abe, Wolfgang Brandner, Timothy D. Brandt, Michael Bonnefoy, Joseph C. Carson, Jeffrey Chilcote, Thayne Currie, Markus Feldt, Miwa Goto, Tyler Groff, Olivier Guyon, Yutaka Hayano, Masahiko Hayashi, Thomas Henning, Klaus W. Hodapp, Miki Ishii, Masanori Iye, Markus Janson, Nemanja Jovanovic, Ryo Kandori, Jeremy Kasdin, Gillian R. Knapp, Julien Lozi, Frantz Martinache, Taro Matsuo, Michael W. Mcelwain, Shoken Miyama, Jun-ichi Morino, Amaya Moro-martin, Takao Nakagawa, Tetsuo Nishimura, Tae-soo Pyo, Evan A. Rich, Eugene Serabyn, Hiroshi Suto, Ryuji Suzuki, Naruhisa Takato, Hiroshi Terada, Christian Thalmann, Daigo Tomono, Edwin L. Turner, Makoto Watanabe, Toru Yamada, Hideki Takami, Tomonori Usuda, Taichi Uyama, Motohide Tamura

        2019.11

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    Language:English  

    The SR24 multi-star system hosts both circumprimary and circumsecondary
    disks, which are strongly misaligned from each other. The circumsecondary disk
    is circumbinary in nature. Interestingly, both disks are interacting, and they
    possibly rotate in opposite directions. To investigate the nature of this
    unique twin disk system, we present 0.''1 resolution near-infrared polarized
    intensity images of the circumstellar structures around SR24, obtained with
    HiCIAO mounted on the Subaru 8.2 m telescope. Both the circumprimary disk and
    the circumsecondary disk are resolved and have elongated features. While the
    position angle of the major axis and radius of the NIR polarization disk around
    SR24S are 55$^{\circ}$ and 137 au, respectively, those around SR24N are
    110$^{\circ}$ and 34 au, respectively. With regard to overall morphology, the
    circumprimary disk around SR24S shows strong asymmetry, whereas the
    circumsecondary disk around SR24N shows relatively strong symmetry. Our NIR
    observations confirm the previous claim that the circumprimary and
    circumsecondary disks are misaligned from each other. Both the circumprimary
    and circumsecondary disks show similar structures in $^{12}$CO observations in
    terms of its size and elongation direction. This consistency is because both
    NIR and $^{12}$CO are tracing surface layers of the flared disks. As the radius
    of the polarization disk around SR24N is roughly consistent with the size of
    the outer Roche lobe, it is natural to interpret the polarization disk around
    SR24N as a circumbinary disk surrounding the SR24Nb-Nc system.

    DOI: 10.3847/1538-3881/ab5850

    arXiv

  2. Point Spread Function of Hexagonally Segmented Telescopes by New Symmetrical Formulation

    Satoshi Itoh, Taro Matsuo, Shibai Hiroshi, Takahiro Sumi

        2018.11

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    A point spread function of hexagonally segmented telescopes is derived by a
    new symmetrical formulation. By introducing three variables on a pupil plane,
    the Fourier transform of pupil functions is derived by a three-dimensional
    Fourier transform. The permutations of three variables correspond to those of a
    regular triangle's vertices on the pupil plane. The resultant diffraction
    amplitude can be written as a product of two functions of the three variables;
    the functions correspond to the sinc function and Dirichlet kernel used in the
    basic theory of diffraction gratings. The new expression makes it clear that
    hexagonally segmented telescopes are equivalent to diffraction gratings in
    terms of mathematical formulae.

    DOI: 10.1093/mnras/sty3052

    arXiv

Presentations 11

  1. Behind coevolution of life and Earth

    T.Matsuo, M. Kumiko, Y. Fujii, S. Kanno

    The 47th Annual Meeting of The Society for the Study of the Origin and Evolution of Life Japan  2023.3.28 

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    Event date: 2023.3

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  2. The hypothesis for green sea: Excitation energy transfer in light-harvesting antenna of cyanobacteria

    R. Tsuji, K. J. Fujimoto, T. Yanai, K. Itoh, S. Kanno, Y. Fujii, and T. Matsuo

    The 47th Annual Meeting of The Society for the Study of the Origin and Evolution of Life Japan  2023.3.28 

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    Event date: 2023.3

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  3. The green sea hypothesis: oxidation of iron ions by photosynthesis of cyanobacteria and changes of the light transmittance in the sea

    S. Takeda, Y. Fujii, T. Matsuo, K. Ito, S. Kanno, and T. Kogiso

    The 47th Annual Meeting of The Society for the Study of the Origin and Evolution of Life Japan  2023.3.28 

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    Event date: 2023.3

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  4. The light-harvesting strategies in cyanobacteria, which triggered the great oxidation event

    K. Ito, T. Matsuo, S. Kanno, Y. Fujii, R. Tsuji, K. J. Fujimoto, Y. Fujita, and H. Miyashita

    The 47th Annual Meeting of The Society for the Study of the Origin and Evolution of Life Japan  2023.3.28 

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    Event date: 2023.3

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  5. Does the phosphorus acquisition mechanism of photosynthetic organisms co-evolve with the global phosphorus environment?

    S. Kanno, K. Ito, Y. Fujii, and T. Matsuo

    The 47th Annual Meeting of The Society for the Study of the Origin and Evolution of Life Japan  2023.3.28 

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    Event date: 2023.3

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  6. Space-based imaging of planets with SPICE Invited International coauthorship International conference

    T, Matsuo

    Exploring Exoplanets with Interferometry  2022.11.29  Caltech

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    Event date: 2022.11 - 2022.12

    Language:English   Presentation type:Symposium, workshop panel (nominated)  

    Venue:Caltech   Country:United States  

  7. Callback talk to the TRLs in talk (1) and what shape we are in. What needs to be done next Invited International coauthorship International conference

    T, Matsuo

    Exploring Exoplanets with Interferometry  2022.11.30  Caltech

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    Event date: 2022.11 - 2022.12

    Language:English   Presentation type:Symposium, workshop panel (nominated)  

    Venue:Caltech   Country:United States  

  8. 赤外線干渉計SEIRIOSのための観測手法の考案とミッション機器の設計

    松尾太郎、五十里哲司、近藤宙貴、太田峻介、原健介、山室智康、中須賀真一

    第66回宇宙科学連合講演会  2022.10.31  日本航空宇宙学会

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    Event date: 2022.10 - 2022.11

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:熊本   Country:Japan  

  9. 宇宙赤外線干渉計ミッションSEIRIOS実現に向けた高精度な光路長制御手法

    近藤宙貴、五十里哲、松尾太郎、中須賀真一

    第66回宇宙科学連合講演会  2022.10.31  日本航空宇宙学会

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    Event date: 2022.10 - 2022.11

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:熊本   Country:Japan  

  10. 回折限界のInner Working Angleを持つ新しいコロナグラフ原理の確認実験

    伊藤哲司、松尾太郎、太田峻介、池田優二、小島礼己、山田亨、住貴宏

    日本天文学会2022年秋季年会  2022.9.15  天文学会

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    Event date: 2022.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:新潟大学   Country:Japan  

  11. 回折限界のInner Working Angleを持つ新しいコロナグラフ原理の確認実験

    太田峻介、松尾太郎、伊藤哲司、叶哲夫、池田優二、小島礼己、山田亨、住貴宏

    日本天文学会2022年秋季年会  2022.9.15  天文学会

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    Event date: 2022.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:新潟大学   Country:Japan  

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Research Project for Joint Research, Competitive Funding, etc. 1

  1. 革新的分光技術による宇宙生命探査

    2021.4 - 2024.3

    JST  創発的研究支援事業 

    松尾太郎

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    Authorship:Principal investigator  Grant type:Competitive

KAKENHI (Grants-in-Aid for Scientific Research) 9

  1. Performance verification of densified pupil interferometry on formation flight simulator Pyxis toward space infrared interferometers

    Grant number:23KK0059  2023.9 - 2027.3

    Grants-in-Aid for Scientific Research  Fund for the Promotion of Joint International Research (International Collaborative Research)

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    Authorship:Principal investigator 

    Grant amount:\20410000 ( Direct Cost: \15700000 、 Indirect Cost:\4710000 )

  2. Study of the coevolution of light environment on the Earth and the light-harvesting strategies in cyanobacteria

    Grant number:23H01288  2023.4 - 2026.3

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

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    Authorship:Coinvestigator(s) 

  3. Pathfinding of high-precision radial-velocity measurement: from direct measurement of Universe's expansion history to spectroscopy of terrestrial planets

    Grant number:22H00151  2022.4 - 2026.3

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

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    Authorship:Principal investigator 

    Grant amount:\39520000 ( Direct Cost: \30400000 、 Indirect Cost:\9120000 )

  4. Establishment of a method for characterizing Earth-like planets

    Grant number:19H00700  2019.4 - 2022.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    Matsuo Taro

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    Authorship:Principal investigator 

    Grant amount:\42900000 ( Direct Cost: \33000000 、 Indirect Cost:\9900000 )

    This research aims to detect the thermal emission and atmospheric absorption of terrestrial exoplanets orbiting late-type stars in the vicinity of the solar system, realizing highly stable spectrophotometric observations in the mid-infrared. In order to realize the highly stable spectroscopy in the mid-infrared, we experimentally developed a densified pupil spectrograph, which forms a spectrum of the pupil plane optically conjugated to the entrance pupil and in principle can achieve high spectrophotometric precision. We developed a cryogenic testbed for demonstration and evaluation of the densified pupil spectrograph at NASA Ames Research Center. Through this experiment, we succeeded in forming the densified pupil spectroscopic image on the detection plane and obtained a stability of 10 parts-per-million (ppm) for a long-term observation by combining a mid-infrared Si:As detector for James Webb Space Telescope with the densified pupil spectrograph.

  5. Hi-resolution Imaging of Far-Infrared Point Sources with Balloon-Borne Interferometer

    Grant number:18H01255  2018.4 - 2021.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Shibai Hiroshi

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    Authorship:Coinvestigator(s) 

    FITE (Far-infrared Interferometric Telescope Experiment) is a balloon-borne telescope on a stratospheric balloon for science, and was scheduled to be launched from the base at Alice Springs, Australia. The purpose was arc-second scale imaging of late-type red supergiants. The launch was not executed due to unsuitable weather during that season. The telescope is maintained for the next opportunity. This research demonstrated the method of the optical adjustment for high-resolution imaging before launch at the site.

  6. Performance verification of high stable spectrograph for characterization of transiting Earth-like planets

    Grant number:17KK0090  2018 - 2019

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Fund for the Promotion of Joint International Research (Fostering Joint International Research)

    Matsuo Taro

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    Authorship:Principal investigator 

    Grant amount:\14300000 ( Direct Cost: \11000000 、 Indirect Cost:\3300000 )

    This study establishes a technology for measuring the atmospheric compositions of Earth-sized planets orbiting nearby stars under a collaboration with NASA Ames Research Center. This technology, which is called "Densified Pupil Spectrograph (DPS)," enables us to perform extremely stable spectroscopy over a few hours under an existence of telescope pointing jitter and deformation of primary mirror. In this study, we built a prototype densified pupil spectrograph at NASA Ames Research Center. We successfully obtained the spectra of the densified sub-pupils on the detector plane and reduced the systematic noise of the spectrograph down to 10 parts-per-million (ppm).

  7. Search for cold exoplanets and free-floating planets by near infrared gravitational microlensing observation

    Grant number:16H06287  2016.4 - 2021.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Specially Promoted Research

    Sumi Takahiro

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    Authorship:Coinvestigator(s) 

    In order to conduct the world's first gravitational microlensing exoplanet survey in the near-infrared, a 1.8-m wide-field PRIME telescope equipped with one of the world's largest near-infrared cameras will be constructed in the Republic of South Africa. All hardware including the telescope, the local dome building, and the infrared camera have been completed, although the local installation of the telescope has been delayed due to COVID-19 and the originally planned observations have not been made. The installation will be completed in FY2022 and the originally planned observations will be made. The observations by the visible light in New Zealand went well and contributed to the discovery of about 50 exoplanets.

  8. High stable spectrograph for characterization of transiting Earth-like exoplanets

    Grant number:16H02164  2016.4 - 2019.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    Matsuo Taro

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    Authorship:Principal investigator 

    Grant amount:\37180000 ( Direct Cost: \28600000 、 Indirect Cost:\8580000 )

    Finding and characterizing the atmospheres of habitable planets orbiting nearby stars is one of the most important scientific goals for observations that will be developed in the 2020s and 2030s. Near- and mid-infrared (IR) spectral features of H2O, CH4, O3, CO2, and other molecule species in the atmospheres of Earth-like planets are expected to have amplitudes of only ~10 parts-per-million (ppm) in transmission or emission spectra when transiting late M-dwarf stars. Here, we proposed a new instrument concept for characterizing transiting Earth-like planets around nearby late-type stars. This concept was named as densified pupil spectrograph. We successfully developed a cryogenic densified pupil testbed optimized for transit observation in mid-infrared wavelength. In addition, this concept was adopted by the future large space mission concept, Origins Space Telescope, and was described as a baseline instrument in the OST proposal for submission to US 2020 decadal survey.

  9. Development of instrument for characterization of extrasolar terretrial planets with Extremely Large Telescopes

    Grant number:25247021  2013.4 - 2017.3

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)  Grant-in-Aid for Scientific Research (A)

    Matsuo Taro, KOTANI Takayuki

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    Authorship:Principal investigator 

    Grant amount:\41080000 ( Direct Cost: \31600000 、 Indirect Cost:\9480000 )

    Extreme Adaptive Optics (ExAO) that corrects wavefront aberration due to the atmospheric turbulence in real-time is crucial for spectroscopic observation of extraterrestrial planets with the next generation ground-based large telescopes such as Thirty Meter Telescope (TMT). In this study, we successfully developed a prototype of the extreme adaptive optics in the room and also proposed a new type of wavefront sensor, which characterizes the performance of the adaptive optics. The developed adaptive optics will be applied to the new telescope built in Okayama prefecture in future.

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Teaching Experience (On-campus) 1

  1. 3年物理学実験

    2020

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    3年生の回路の基本的な特性を理解し、その基本的な理解に基づいて回路を用いて信号取得などを実施する物理学実験である。

Teaching Experience (Off-campus) 5

  1. 先端物理学特論

    2021.4 Nagoya University)

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    Level:Undergraduate (specialized) 

  2. Physics Experiment for Third Year University Students

    2020.4 Nagoya University)

  3. Physics Experiment for First Year University Students

    2018.10 - 2019.10 Osaka University)

  4. Life in the Universe

    2015.10 - 2019.10 Osaka University)

  5. Physics Experiment for Third Year University Students

    2015.10 - 2018.9 Osaka University)

 

Social Contribution 9

  1. 宇宙生命に関するセミナー

    Role(s):Lecturer

    犬山市  2022.3

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    Audience: Schoolchildren, Junior students, High school students

    Type:Seminar, workshop

  2. 宇宙生命に関するセミナー

    Role(s):Lecturer

    岐阜県立斐太高校  2021.5

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    Audience: High school students

    Type:Visiting lecture

  3. 科学三昧inあいち

    Role(s):Advisor, Demonstrator

    2020.12

  4. Delivery class: Search for life in the universe

    Role(s):Lecturer

    2018.11

  5. Delivery class: Search for life in the universe

    Role(s):Lecturer

    2017.12

  6. Delivery class: Search for life in the universe

    Role(s):Lecturer

    2017.12

  7. Delivery class: Search for life in the universe

    Role(s):Lecturer

    2017.10

  8. 太陽系外惑星科学の現在と未来 〜 私がこれから30年かけて取り組みたいこと〜

    Role(s):Lecturer

    高校生天文活動発表会実行委員会  2017.7

  9. 太陽系惑星と太陽系外惑星に関するセミナー

    Role(s):Lecturer

    NPO花山星空ネットワーク  2012.4 - 2017.3

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