宇宙線
高エネルギー宇宙物理学
X-ray Telescope
Supernova Remnants
Supernovae
X-ray Astronomy
Astrophysics
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4 2021 - PresentCollege of Science Department of Physics Assistant Professor
Researcher Profile
Updated on 2022/05/09
宇宙線
高エネルギー宇宙物理学
X-ray Telescope
Supernova Remnants
Supernovae
X-ray Astronomy
Astrophysics
Natural Science / Astronomy
Natural Science / Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics
Discovery of a highly neutronized ejecta clump in the type ia supernova remnant 3C397 Peer-reviewed
Yuken Ohshiro, Hiroya Yamaguchi, Shing Chi Leung, Ken'ichi Nomoto, Toshiki Sato, Takaaki Tanaka, Hiromichi Okon, Robert Fisher, Robert Petre, Brian J. Williams
Astrophysical Journal Letters913 ( 2 ) 1 6 2021
On the Origin of the Asymmetry of the Ejecta Structure and Explosion of G350.1-0.3 Peer-reviewed
Tomoya Tsuchioka, Yasunobu Uchiyama, Ryota Higurashi, Hiroyoshi Iwasaki, Shumpei Otsuka, Shinya Yamada, Toshiki Sato
ASTROPHYSICAL JOURNAL912 ( 2 ) 5 2021
High-entropy ejecta plumes in Cassiopeia A from neutrino-driven convection Peer-reviewed
Toshiki Sato, Keiichi Maeda, Shigehiro Nagataki, Takashi Yoshida, Brian Grefenstette, Brian J. Williams, Hideyuki Umeda, Masaomi Ono, John P. Hughes
Nature592 ( 7855 ) 537 - 540 4 2021
From supernova to supernova remnant: Comparison of thermonuclear explosion models Peer-reviewed
Gilles Ferrand, Donald C. Warren, Masaomi Ono, Shigehiro Nagataki, Friedrich K. Röpke, Ivo R. Seitenzahl, Florian Lach, Hiroyoshi Iwasaki, Toshiki Sato
Astrophysical Journal906 ( 2 ) 10 1 2021
Formation pathway for lonely stripped-envelope supernova progenitors: Implications for Cassiopeia A Peer-reviewed
Ryosuke Hirai, Toshiki Sato, Philipp Podsiadlowski, Alejandro Vigna-Gómez, Ilya Mandel
Monthly Notices of the Royal Astronomical Society499 ( 1 ) 1154 - 1170 1 11 2020
An ejecta kinematics study of kepler's supernova remnant with high-resolution chandra hetg spectroscopy Peer-reviewed
Matthew J. Millard, Jayant Bhalerao, Sangwook Park, Toshiki Sato, John P. Hughes, Patrick Slane, Daniel Patnaude, David Burrows, Carles Badenes
Astrophysical Journal893 ( 2 ) 4 2020
A Subsolar Metallicity Progenitor for Cassiopeia A, the Remnant of a Type IIb Supernova Peer-reviewed
Toshiki Sato, Takashi Yoshida, Hideyuki Umeda, Shigehiro Nagataki, Masaomi Ono, Keiichi Maeda, Ryosuke Hirai, John P. Hughes, Brian J. Williams, Yoshitomo Maeda
ASTROPHYSICAL JOURNAL893 ( 1 ) 4 2020
A Nucleosynthetic Origin for the Southwestern Fe-rich Structure in Kepler's Supernova Remnant Peer-reviewed
Toshiki Sato, Eduardo Bravo, Carles Badenes, John P. Hughes, Brian J. Williams, Hiroya Yamaguchi
ASTROPHYSICAL JOURNAL890 ( 2 ) 2 2020
Concept for an X-ray telescope system with an angular resolution booster Peer-reviewed
Yoshitomo Maeda, Ryo Iizuka, Takayuki Hayashi, Toshiki Sato, Nozomi Nakaniwa, Mai Takeo, Hitomi Suzuki, Manabu Ishida, Shiro Ikeda, Mikio Morii
Publications of the Astronomical Society of Japan71 ( 5 ) 1 10 2019
Genus Statistic Applied to the X-Ray Remnant of SN 1572: Clues to the Clumpy Ejecta Structure of Type Ia Supernovae Peer-reviewed
Toshiki Sato, John P. Hughes, Brian J. Williams, Mikio Morii
ASTROPHYSICAL JOURNAL879 ( 2 ) 7 2019
Concept for an X-ray telescope system with an angular resolution booster Peer-reviewed
Maeda, Y., Iizuka, R., Hayashi, T., Sato, T., Nakaniwa, N., Takeo, M., Suzuki, H., Ishida, M., Ikeda, S., Morii, M.
Publications of the Astronomical Society of Japan71 ( 5 ) 2019
Asymmetric expansion of the Fe ejecta in Kepler's supernova remnant Peer-reviewed
Kasuga Tomoaki, Sato Toshiki, Mori Koji, Yamaguchi Hiroya, Bamba Aya
Publ. Astron. Soc. Japan 8 2018
Vortical Amplification of the Magnetic Field at an Inward Shock of Supernova Remnant Cassiopeia A Peer-reviewed
F. Fraschetti, S. Katsuda, T. Sato, J. R. Jokipii, J. Giacalone
Physical Review Letters120 ( 25 ) 21 6 2018
Inflight Calibration of Hitomi Soft X-ray Spectrometer (2) Point Spread Function Peer-reviewed
Maeda, Yoshitomo, Sato, Toshiki, Hayashi, Takayuki, Iizuka, Ryo, Angelini, Lorella, Asai, Ryota, Furuzawa, Akihiro, Kelley, Richard, Koyama, Shu, Kurashima, Sho, Ishida, Manabu, Mori, Hideyuki, Nakaniwa, Nozomi, Okajima, Takashi, Serlemitsos, Peter J, Tsujimoto, Masahiro, Yaqoob, Tahir
Publ. Astron. Soc. Japan70 ( 2 ) 4 2018
Search for Thermal X-ray Features from the Crab nebula with Hitomi Soft X-ray Spectrometer Peer-reviewed
Hitomi collaboration (including, Toshiki Sato
Publ. Astron. Soc. Japan70 ( 2 ) 4 2018
Hitomi Observations of the LMC SNR N132D: Highly Redshifted X-ray Emission from Iron Ejecta Peer-reviewed
Hitomi collaboration (including, Toshiki Sato
Publ. Astron. Soc. Japan70 ( 2 ) 4 2018
Hitomi X-ray Observation of the Pulsar Wind Nebula G21.5-0.9 Peer-reviewed
Hitomi collaboration (including, Toshiki Sato
Publ. Astron. Soc. Japan70 ( 3 ) 4 2018
In-flight verification of the calibration and performance of the ASTRO-H (Hitomi) soft x-ray spectrometer Peer-reviewed
Maurice A. Leutenegger, Marc Audard, Kevin R. Boyce, Gregory V. Brown, Meng P. Chiao, Megan E. Eckart, Ryuichi Fujimoto, Akihiro Furuzawa, Matteo Guainazzi, Daniel Haas, Takayuki Hayashi, Jan-Willem Den Herder, Ryo Iizuka, Manabu Ishida, Yoshitaka Ishisaki, Naomichi Kikuchi, Caroline A. Kilbourne, Shu Koyama, Sho Kurashima, Yoshitomo Maeda, Maxim Markevitch, Dan Mccammon, Kazuhisa Mitsuda, Hideyuki Mori, Nozomi Nakaniwa, Takashi Okajima, Stéphane Paltani, Robert Petre, F. Scott Porter, Kosuke Sato, Toshiki Sato, Makoto Sawada, Peter J. Serlemitsos, Hiromi Seta, Gary Sneiderman, Yang Soong, Satoshi Sugita, Andrew E. Szymkowiak, Yoh Takei, Makoto Tashiro, Yuzuru Tawara, Masahiro Tsujimoto, Cor P. De Vries, Tomomi Watanabe, Shinya Yamada, Noriko Yamasaki
Journal of Astronomical Telescopes, Instruments, and Systems4 ( 2 ) 1 4 2018
In-flight calibration of Hitomi Soft X-ray Spectrometer. (3) Effective area Peer-reviewed
Masahiro Tsujimoto, Takashi Okajima, Megan E. Eckart, Takayuki Hayashi, Akio Hoshino, Ryo Iizuka, Richard L. Kelley, Caroline A. Kilbourne, Maurice A. Leutenegger, Yoshitomo Maeda, Hideyuki Mori, Frederick S. Porter, Kosuke Sato, Toshiki Sato, Peter J. Serlemitsos, Andrew Szymkowiak, Tahir Yaqoob
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN70 ( 2 ) 3 2018
In-orbit performance of the soft X-ray imaging system aboard Hitomi Peer-reviewed
Nakajima Hiroshi, Maeda Yoshitomo, Uchida Hiroyuki, Tanaka Takaaki, Tsunemi Hiroshi, Hayashida Kiyoshi, Tsuru Takeshi G, Dotani Tadayasu, Nagino Ryo, Inoue Shota, Ozaki Masanobu, Tomida Hiroshi, Natsukari Chikara, Ueda Shutaro, Mori Koji, Yamauchi Makoto, Hatsukade Isamu, Nishioka Yusuke, Sakata Miho, Beppu Tatsuhiko, Honda Daigo, Nobukawa Masayoshi, Hiraga Junko S, Kohmura Takayoshi, Murakami Hiroshi, Nobukawa, Kumiko K, Bamba Aya, Doty John P, Iizuka Ryo, Sato Toshiki, Kurashima Sho, Nakaniwa Nozomi, Asai Ryota, Ishida Manadu, Mori Hideyuki, Soong Yang, Okajima Takashi, Serlemitsos Peter, Tawara Yuzuru, Mitsuishi Ikuyuki, Ishibashi Kazunori, Tamura Keisuke, Hayashi Takayuki, Furuzawa Akihiro, Sugita Satoshi, Miyazawa Takuya, Awaki Hisamitsu, Miller Eric D, Yamaguchi Hiroya
Publications of the Astronomical Society of Japan70 ( 2 ) 3 2018
Ground-based x-ray calibration of the Astro-H/Hitomi soft x-ray telescopes Peer-reviewed
Ryo Iizuka, Takayuki Hayashi, Yoshitomo Maeda, Manabu Ishida, Kazuki Tomikawa, Toshiki Sato, Naomichi Kikuchi, Takashi Okajima, Yang Soong, Peter J. Serlemitsos, Hideyuki Mori, Takanori Izumiya, Sari Minami
Journal of Astronomical Telescopes, Instruments, and Systems4 ( 1 ) 1 1 2018
On-ground calibration of the Hitomi Hard X-ray Telescopes Peer-reviewed
Hideyuki Mori, Takuya Miyazawa, Hisamitsu Awaki, Hironori Matsumoto, Yasunori Babazaki, Ayako Bandai, Tadatsugu Demoto, Akihiro Furuzawa, Yoshito Haba, Takayuki Hayashi, Ryo Iizuka, Kazunori Ishibashi, Manabu Ishida, Naoki Ishida, Masayuki Itoh, Toshihiro Iwase, Hiroyoshi Kato, Hiroaki Kobayashi, Tatsuro Kosaka, Hideyo Kunieda, Shou Kurashima, Daichi Kurihara, Yuuji Kuroda, Yoshitomo Maeda, Yoshifumi Meshino, Ikuyuki Mitsuishi, Yuusuke Miyata, Housei Nagano, Yoshiharu Namba, Yasushi Ogasaka, Keiji Ogi, Takashi Okajima, Shigetaka Saji, Fumiya Shimasaki, Takuro Sato, Toshiki Sato, Naotsugu Shima, Satoshi Sugita, Yoshio Suzuki, Kenji Tachibana, Sasagu Tachibana, Shun'Ya Takizawa, Keisuke Tamura, Yuzuru Tawara, Kazuki Tomikawa, Tatsuharu Torii, Kentaro Uesugi, Koujun Yamashita, Shigeo Yamauchi
Journal of Astronomical Telescopes, Instruments, and Systems4 ( 1 ) 011210-1 - 011210-22 1 1 2018
X-Ray Measurements of the Particle Acceleration Properties at Inward Shocks in Cassiopeia A Peer-reviewed
Toshiki Sato, Satoru Katsuda, Mikio Morii, Aya Bamba, John P. Hughes, Yoshitomo Maeda, Manabu Ishida, Federico Fraschetti
ASTROPHYSICAL JOURNAL853 ( 1 ) 1 2018
Freely Expanding Knots of X-Ray-emitting Ejecta in Kepler's Supernova Remnant Peer-reviewed
Toshiki Sato, John P. Hughes
ASTROPHYSICAL JOURNAL845 ( 2 ) 8 2017
Direct Ejecta Velocity Measurements of Tycho's Supernova Remnant Peer-reviewed
Toshiki Sato, John P. Hughes
ASTROPHYSICAL JOURNAL840 ( 2 ) 5 2017
Multi-year X-Ray Variations of Iron-K and Continuum Emissions in the Young Supernova Remnant Cassiopeia A Peer-reviewed
Toshiki Sato, Yoshitomo Maeda, Aya Bamba, Satoru Katsuda, Yutaka Ohira, Ryo Yamazaki, Kuniaki Masai, Hironori Matsumoto, Makoto Sawada, Yukikatsu Terada, John P. Hughes, Manabu Ishida
ASTROPHYSICAL JOURNAL836 ( 2 ) 2 2017
An angular-resolution booster on the broadband X-ray telescope system Peer-reviewed
Yoshitomo Maeda, Ryo Iizuka, Toshiki Sato, Manabu Ishida, Takayuki Hayashi, Ryoko Nakamura
OPTICS FOR EUV, X-RAY, AND GAMMA-RAY ASTRONOMY VIII10399 2017
Reflectivity around the gold L-edges of x-ray reflector of the soft x-ray telescope onboard ASTRO-H
Yoshitomo Maeda, Naomichi Kikuchi, Sho Kurashima, Manabu Ishida, Ryo Iizuka, Takayuki Hayashi, Takashi Okajima, Hironori Matsumoto, Ikuyuki Mitsuishi, Shigetaka Saji, Toshiki Sato, Sasagu Tachibana, Hideyuki Mori, Finn Christensen, Nicolai Brejnholt, Kiyofumi Nitta, Tomoya Uruga
OPTICS FOR EUV, X-RAY, AND GAMMA-RAY ASTRONOMY VIII10399 id. 99053Z 2017
Atomic scattering factor of the ASTRO-H (Hitomi) SXT reflector around the gold's L edges Peer-reviewed
Naomichi Kikuchi, Sho Kurashima, Manabu Ishida, Ryo Iizuka, Yoshitomo Maeda, Takayuki Hayashi, Takashi Okajima, Hironori Matsumoto, Ikuyuki Mitsuishi, Shigetaka Saji, Toshiki Sato, Sasagu Tachibana, Hideyuki Mori, Finn Christensen, Nicolai Brejnholt, Kiyofumi Nitta, Tomoya Uruga
OPTICS EXPRESS24 ( 22 ) 25548 - 25564 10 2016
Examining the angular resolution of the ASTRO-H's soft x-ray telescopes Peer-reviewed
Toshiki Sato, Ryo Iizuka, Manabu Ishida, Naomichi Kikuchi, Yoshitomo Maeda, Sho Kurashima, Nozomi Nakaniwa, Kazuki Tomikawa, Takayuki Hayashi, Hideyuki Mori, Takashi Okajima, Peter J. Serlemitsos, Yang Soong, Takanori Izumiya, Sari Minami
JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS2 ( 4 ) 10 2016
The ASTRO-H SXT performance to the large off-set angles Peer-reviewed
Toshiki Sato, Ryo Iizuka, Hideyuki Mori, Takayuki Hayashi, Yoshitomo Maeda, Manabu Ishida, Naomichi Kikuchi, Sho Kurashima, Nozomi Nakaniwa, Takashi Okajima, Yang Soong, Peter J. Serlemitosos
SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY9905 2016
Point spread function of ASTRO-H Soft X-ray Telescope (SXT) Peer-reviewed
Takayuki Hayashi, Toshiki Sato, Naomichi Kikuchi, Ryo Iizuka, Yoshitomo Maeda, Manabu Ishida, Sho Kurashima, Nozomi Nakaniwa, Takashi Okajima, Hideyuki Mori, Yang Soong, Peter J. Serlemitosos
SPACE TELESCOPES AND INSTRUMENTATION 2016: ULTRAVIOLET TO GAMMA RAY9905 2016
First peek of ASTRO-H Soft X-ray Telescope (SXT) in-orbit performance Peer-reviewed
Takashi Okajima, Yang Soong, Peter Serlemitsos, Hideyuki Mori, Larry Olsen, David Robinson, Richard Koenecke, Bill Chang, Devin Hahne, Ryo Iizuka, Manabu Ishida, Yoshitomo Maeda, Toshiki Sato, Naomichi Kikuchi, Sho Kurashima, Nozomi Nakaniwa, Takayuki Hayashi, Kazunori Ishibashi, Takuya Miyazawa, Kenji Tachibana, Keisuke Tamura, Akihiro Furuzawa, Yuzuru Tawara, Satoshi Sugita
Proceedings of SPIE - The International Society for Optical Engineering9905 2016
In-flight verification of the calibration and performance of the ASTRO-H (Hitomi) Soft X-Ray Spectrometer Peer-reviewed
Maurice A. Leutenegger, Marc Audard, Kevin R. Boyce, Gregory V. Brown, Meng P. Chiao, Megan E. Eckart, Ryuichi Fujimoto, Akihiro Furuzawa, Matteo Guainazzi, Daniel Haas, Jan-Willem Den Herder, Takayuki Hayashi, Ryo Iizuka, Manabu Ishida, Yoshitaka Ishisaki, Richard L. Kelley, Naomichi Kikuchi, Caroline A. Kilbourne, Shu Koyama, Sho Kurashima, Yoshitomo Maeda, Maxim Markevitch, Dan McCammon, Kazuhisa Mitsuda, Hideyuki Mori, Nozomi Nakaniwa, Takashi Okajima, Stéphane Paltani, Robert Petre, F. Scott Porter, Kosuke Sato, Toshiki Sato, Makoto Sawada, Peter J. Serlemitsos, Hiromi Seta, Gary Sneiderman, Yang Soong, Satoshi Sugita, Andrew E. Szymkowiak, Yoh Takei, Makoto Tashiro, Yuzuru Tawara, Masahiro Tsujimoto, Cor P. De Vries, Tomomi Watanabe, Shinya Yamada, Noriko Yamasaki
Proceedings of SPIE - The International Society for Optical Engineering9905 2016
Reflectivity around the gold L-edges of x-ray reflector of the soft x-ray telescope onboard ASTRO-H
Yoshitomo Maeda, Naomichi Kikuchi, Sho Kurashima, Manabu Ishida, Ryo Iizuka, Takayuki Hayashi, Takashi Okajima, Hironori Matsumoto, Ikuyuki Mitsuishi, Shigetaka Saji, Toshiki Sato, Sasagu Tachibana, Hideyuki Mori, Finn Christensen, Nicolai Brejnholt, Kiyofumi Nitta, Tomoya Uruga
Proceedings of SPIE - The International Society for Optical Engineering9905 id. 99053Y 2016
Upgrade of the 30-m x-ray pencil beam line at the Institute of Space and Astronautical Science Peer-reviewed
Takayuki Hayashi, Toshiki Sato, Naomichi Kikuchi, Sho Kurashima, Nozomi Nakaniwa, Takuro Sato, Ryo Iizuka, Yoshitomo Maeda, Manabu Ishida
JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS1 ( 4 ) 10 2015
Thermal stress test of the depth-graded platinum/carbon reflectors Peer-reviewed
Yoshitomo Maeda, Kou Ichihara, Hiroaki Kan, Yu Shionome, Takuro Sato, Toshiki Sato, Takayuki Hayashi, Manabu Ishida, Yoshiharu Namba, Hideaki Takahashi, Takuya Miyazawa, Kazunori Ishibashi, Michito Sakai, Satoshi Sugita, Yoshito Haba, Hironori Matsumoto, Hideyuki Mori
Journal of Astronomical Telescopes, Instruments, and Systems1 ( 3 ) id. 034001 1 7 2015
Hard x-ray telescopes to be onboard ASTRO-H Peer-reviewed
Hisamitsu Awaki, Hideyo Kunieda, Manabu Ishida, Hironori Matsumoto, Yasunori Babazaki, Tadatsugu Demoto, Akihiro Furuzawa, Yoshito Haba, Takayuki Hayashi, Ryo Iizuka, Kazunori Ishibashi, Naoki Ishida, Masayuki Itoh, Toshihiro Iwase, Tatsuro Kosaka, Daichi Kurihara, Yuuji Kuroda, Yoshitomo Maeda, Yoshifumi Meshino, Ikuyuki Mitsuishi, Yuusuke Miyata, Takuya Miyazawa, Hideyuki Mori, Housei Nagano, Yoshiharu Namba, Yasushi Ogasaka, Keiji Ogi, Takashi Okajima, Shigetaka Saji, Fumiya Shimasaki, Takuro Sato, Toshiki Sato, Satoshi Sugita, Yoshio Suzuki, Kenji Tachibana, Sasagu Tachibana, Shunya Takizawa, Keisuke Tamura, Yuzuru Tawara, Tatsuharu Torii, Kentato Uesugi, Koujun Yamashita, Shigeo Yamauchi
Applied Optics53 ( 32 ) 7664 - 7676 10 11 2014
ASTRO-H Soft X-ray Telescope (SXT) Peer-reviewed
Yang Soong, Takashi Okajima, Peter J. Serlemitsos, Stephen L. Odell, Brian D. Ramsey, Mikhail V. Gubarev, Manabu Ishida, Yoshitomo Maeda, Ryo Iizuka, Takayuki Hayashi, Yuzuru Tawara, Akihiro Furuzawa, Hideyuki Mori, Takuya Miyazawa, Hideyo Kunieda, Hisamitsu Awaki, Satoshi Sugita, Keisuke Tamura, Kazunori Ishibashi, Takanori Izumiya, Sari Minami, Toshiki Sato, Kazuki Tomikawa, Naomichi Kikuchi, Toshihiro Iwase
SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY9144 2014
Ground-based X-ray calibration of the Astro-H soft X-ray telescopes Peer-reviewed
Ryo Iizuka, Takayuki Hayashi, Yoshitomo Maeda, Manabu Ishida, Kazuki Tomikawa, Toshiki Sato, Naomichi Kikuchi, Takashi Okajima, Yang Soong, Peter J. Serlemitosos, Hideyuki Mori, Takanori Izumiya, Sari Minami
SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY9144 2014
Upgrade of the thirty-meter x-ray pencil beam line at the institute of space and astronautical science Peer-reviewed
Takayuki Hayashi, Toshiki Sato, Kazuki Tomikawa, Naomichi Kikuchi, Takuro Sato, Ryo Iizuka, Yoshitomo Maeda, Manabu Ishida
SPACE TELESCOPES AND INSTRUMENTATION 2014: ULTRAVIOLET TO GAMMA RAY9144 2014
Assembly of a MEMS-based Wolter type-I X-ray optic toward a future planetary exploration mission Peer-reviewed
Ikuyuki Mitsuishi, Yuichiro Ezoe, Tomohiro Ogawa, Takuya Kakiuchi, Masahiro Ikuta, Takayuki Hayashi, Toshiki Sato, Takaya Ohashi, Kazuhisa Mitsuda, Kohei Morishita, Kazuo Nakajima
International Conference on Optical MEMS and Nanophotonics 115 - 116 2013
X線観測によるケプラーの超新星残骸の明るい塊構造の三次元速度測定
Sato Toshiki
日本天文学会秋季年会 9 2017
In-flight Calibration Status of the Soft X-ray Telescopes (SXTs) onboad the Hitomi Satellite International conference
Toshiki Sato, lf, Hi, omi's, S
12th IACHEC meeting 27 3 2017
カシオペア A の逆行衝撃波の固有運動とスペクトル変動の調査
Sato Toshiki
日本天文学会春季年会 3 2017
Plasma Study of the Cassiopeia A Supernova Remnant International conference
Sato Toshiki
Spectroscopy of Cosmic Plasma in the Era of ASTRO-H 8 2015
Time variation of Cassiopeia A and a new evidence of the variation International conference
Sato Toshiki
COSPAR MOSCOW 2014 8 2014
44Ti専用硬X線望遠鏡で明らかにする銀河系内陽電子の起源
日本学術振興会 科学研究費助成事業 若手研究
佐藤 寿紀
4 2019 - 3 2023
Grant number:19K14749
Authorship:Principal investigator Grant type:Competitive
Grant amount:\4160000 ( Direct Cost: \3200000 、 Indirect Cost:\960000 )
本研究では、銀河系内陽電子起源の有力候補として考えられているIa型超新星(Double Detonation model)の観測的証拠を掴むための観測機器の開発と観測研究を行なっている。Ia型超新星モデルの中でも、厚いHe外層の核燃焼の衝撃波で白色矮星の爆発を誘発するタイプのIa型超新星では、その外層の核燃焼時に大量の44Tiが合成されると考えられており、その崩壊時に放出される陽電子が我々の銀河内で供給されている可能性がある。つまり、Ia型超新星で44Tiが合成されている現場を捉えられれば、このIa型超新星の陽電子起源の最も強い証拠になる。
我々は、この44Ti崩壊γ線(68 keV, 78 keV)の観測精度の飛躍的向上のため、ニューハンプシャー大やNASAと協力し、γ線TESカロリメータと硬X線望遠鏡を組み合わせた気球実験計画を進めている。今年度は米国の気球計画にプロポーザルを提出したが、未採択となったため、次回に向け再度提案書を作成している。硬X線望遠鏡の開発に関しては、多層膜研究をNASA/GSFCで開始した。Ni コーティングを可能にするため、新たなスパッタ装置を導入し、現在その立ち上げ作業を行なっており、次の年度から実際に膜付け研究を行う予定である。
観測研究に関しては、Ia型超新星の残骸(ケプラーの超新星残骸)の膨張速度を Chandra 衛星のグレーティング観測で測定し、その三次元構造に迫った(Matthew et al. 2020, ApJ)。加えて、Ia型超新星の残骸の構造と超新星シミュレーションの構造を直接比較できる手法を開発した(Sato et al. 2019, ApJ)。これらの構造研究の他にも、超新星残骸内の元素組成に着目し、その爆発機構へ迫る研究を行なった(Sato et al. 2020a,b)。
Constraint of the Nuclear Burning Condition in the Deep Core of the Massive Star’s Explosion
RIKEN
Sato Toshiki
Ia型超新星の爆発機構解明に向けた観測的三次元モデルの構築
日本学術振興会 科学研究費助成事業 研究活動スタート支援
佐藤 寿紀
8 2018 - 3 2020
Grant number:18H05865
Grant amount:\2210000 ( Direct Cost: \1700000 、 Indirect Cost:\510000 )
X線を用いた超新星残骸の観測研究に関して二本の共著論文を査読論文として出版し、一本の主著論文と一本の共著論文を査読誌へ投稿した。また、国際学会での口頭発表一件と天文学会年会でのポスター発表一件を行った。
本研究ではIa型超新星残骸の三次元的構造から、その爆発機構の解明を目指した。特に、今年度は超新星残骸内に存在する塊状構造に着目し、これらがどのようにして形成されたかを議論するため「ジーナス統計」という手法を世界で初めて超新星残骸の観測研究に適応し、Ia型超新星残骸の三次元流体モデルとの比較を行った。結果として、これらの塊構造は爆発初期から存在していた事が示唆され、その形成過程は爆発機構を議論する上でも非常に重要なプロセスである事を指摘できた。本研究内容に関しては、米国 Astrophysical Journal 誌にて、現在査読中である。
加えて、Ia型超新星残骸内のドップラー偏移に着目した三次元構造の調査に関連する研究も順調に進める事ができた(Kasuga, Sato+19, PASJ & Millard+19, submitted to ApJ)。これらの結果は今後、三次元超新星モデルとの比較により、爆発機構の同定の重要な情報になりうる。
その他にも、超新星残骸 Cassiopeia A 内で起こる非熱的放射(宇宙線電子からのシンクロトロン放射)の時間変動に関して、多数の塊状の構造内を衝撃波が伝搬する際の、渦状乱流によって解析的に説明できる事を示し、Physical Review Letters 誌に掲載された(Fraschetti, Katsuda, Sato+18)。
44Tiの合成量に基づいた対称・非対称な重力崩壊型超新星爆発の元素合成の解明
日本学術振興会 科学研究費助成事業 特別研究員奨励費
佐藤 寿紀
4 2016 - 3 2018
Grant number:16J03448
Authorship:Principal investigator Grant type:Competitive
Grant amount:\1300000 ( Direct Cost: \1300000 )
本研究の目的は、重力崩壊型超新星の44Tiの合成量を調査することで、爆発モデルに伴う元 素合成過程を明らかにすることであり、その実現のために、実験・観測の両面から研究を行った。本年度の研究成果を以下の3つに分けて記す。
(I) 2016年に打ち上げられたひとみ衛星の軌道上キャリブレーションと観測研究を行った。ひとみ衛星に搭載された超精密X線分光システムは、Cassiopeia A内の44Tiが崩壊した後の44ScからのX線輝線検出が期待されていた。しかしながら、Cassiopeia A の観測前に運用停止となってしまったため、他の重力崩壊型超新星の残骸である、カニ星雲、G21.5-0.9、N132Dの観測研究を行った。カニ星雲では、爆発噴出物由来の熱的X線放射をこれまでにない精度で上限値を決める事に成功し、その爆発起源の推定を行った。N132Dに関しては、爆発噴出物の鉄が偏った方向に飛び交っている事を初めて示し、爆発の非対称性を議論する事が出来た。観測結果は、査読論文としてPASJから出版された。
(II) Cassiopeia A は重力崩壊型超新星であり、本研究の鍵を握る44Tiからの崩壊ガンマ線が硬X線観測で発見されている数少ないサンプルである。今年度私は、この天体内の衝撃波で加速された宇宙線電子からの非熱的放射に着目した研究を行った。本研究では逆行する衝撃波に着目し、通常の前進している順行衝撃波よりも、それらの衝撃波速度が早くなっていることを観測的に初めて明らかにした。この結果は、査読論文(主著)として、APJ誌に掲載された。
(III) Ia型超新星残骸ティコ、ケプラーの膨張速度をドップラー効果を用いる事で測定することに成功し、その三次元的な空間構造に迫る研究を行った。結果として、ティコとケプラーではそれぞれ対称、非対称な膨張であることがわかって来た。これらの研究内容は、それぞれ2本の査読論文(主著)として、APJ誌に掲載された。
Supernova simulations reveal how stellar explosions shape debris clouds Internet
3 2021
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Phys.org 10 2020
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sorae 10 2019
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