鉄輝線精密分光による銀河宇宙線加速の初期機構解明

• Project/Area Number: 16J00548
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Nara Women's University
• Principal Investigator: 信川 久実子 奈良女子大学, 理学部, 特別研究員(PD)
• Project Period (FY): 2016-04-22 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000); Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
• Keywords: X線天文学 / 宇宙線 / X線CCD / 低エネルギー宇宙線 / 超新星残骸 / 銀河面X線放射

Outline of Annual Research Achievements

銀河宇宙線の起源と考えられている超新星残骸 (SNR)において低エネルギー宇宙線を探査するため、宇宙線が分子雲に衝突して放射される中性鉄輝線の調査を「すざく」衛星を用いて行なってきた。受入研究室の学生と共同研究を行い、今年度はIC443とW51Cで有意な中性鉄輝線を発見した。どちらの天体も中性鉄輝線の分布は分子雲と相関していた。近傍に分子雲を照らす明るいX線天体は存在しない。これらの事実から、中性鉄輝線の起源は低エネルギー宇宙線であると結論した。宇宙線起源の中性鉄輝線が見つかっている超新星残骸のいくつかは、ガンマ線放射も見つかっている。低エネルギー宇宙線は衝撃波面の近傍に留まったままわずか100年程で冷えるが、高エネルギー宇宙線は冷却に1万年かかり遠くへ拡散すると考えられる。この描像のもと、理論分野の研究者と共にモデルを構築し、ガンマ線スペクトルと中性鉄輝線の強度を統一的に説明した。中性鉄輝線で低エネルギー宇宙線を測定する手法は注目されており、今年度は国際会議で2件、国内会議で1件の招待講演を行なった。さらに「すざく」のデータを調査している中で、半径6分という大きな円環状のX線放射を発見した。詳細な解析の結果、その正体が円環の中心にある突発天体から出たX線フレアのダスト散乱光であることを見出した。この結果も査読付き論文として発表した。2021年度打ち上げ予定の「XRISM」衛星搭載X線CCDの開発も行なった。衛星搭載品の地上試験を行い、そのデータを用いて、受入研究室の学生との共同研究を通して新しい較正手法を確立した。これまでの手法では、異なるクロックモードで取得したデータは異なるパラメータで較正する必要があったが、新しい較正手法は共通のパラメータで較正を行うことができる。この方法は衛星打ち上げ後、観測データの標準的な解析方法として採用される予定である。

Research Progress Status

令和元年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和元年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] NASA/Massachusetts Institute of Technology(米国)
• [Int'l Joint Research] NASA/Massachusetts Institute of Technology(米国)
• [Journal Article] Discovery of annular X-ray emission centered on MAXI?J1421-613: Dust-scattering X-rays? (2020)
  • Author(s): Nobukawa Kumiko K、Nobukawa Masayoshi、Yamauchi Shigeo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 72 Issue: 2
  • DOI: 10.1093/pasj/psaa007
  • Peer Reviewed
• [Journal Article] Neutral iron line in the supernova remnant IC?443 and implications for MeV cosmic rays (2019)
  • Author(s): Nobukawa Kumiko K、Hirayama Arisa、Shimaguchi Aika、Fujita Yutaka、Nobukawa Masayoshi、Yamauchi Shigeo
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 71 Issue: 6 Pages: 115-115
  • DOI: 10.1093/pasj/psz099
  • Peer Reviewed
• [Journal Article] Characterization of diffuse X-ray emission from IGR?J17448$-$3232: an implication of a line-of-sight merging activity (2019)
  • Author(s): Watanabe Shoko、Yamauchi Shigeo、Nobukawa Kumiko K、Akamatsu Hiroki
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 71 Issue: 6
  • DOI: 10.1093/pasj/psz098
  • Peer Reviewed
• [Journal Article] Interaction between molecular clouds and MeV?TeV cosmic-ray protons escaped from supernova remnants (2019)
  • Author(s): Makino Ken、Fujita Yutaka、Nobukawa Kumiko K、Matsumoto Hironori、Ohira Yutaka
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 71 Issue: 4 Pages: 78-78
  • DOI: 10.1093/pasj/psz058
  • Peer Reviewed
• [Journal Article] Radiation hardness of a p-channel notch CCD developed for the X-ray CCD camera onboard the XRISM satellite (2019)
  • Author(s): Kanemaru Y., Sato J., Mori K. et al.
  • Journal Title: Journal of Instrumentation Volume: 14 Issue: 04 Pages: C04003-C04003
  • DOI: 10.1088/1748-0221/14/04/c04003
  • Peer Reviewed
• [Journal Article] Measurement of Low-Energy Cosmic Rays via the Neutral Iron Line (2019)
  • Author(s): Nobukawa Kumiko K.、Saji Shigetaka、Hirayama Arisa、Nobukawa Masayoshi、Yamauchi Shigeo、Matsumoto Hironori、Koyama Katsuji
  • Journal Title: Journal of Physics: Conference Series Volume: 1181 Pages: 012040-012040
  • DOI: 10.1088/1742-6596/1181/1/012040
  • Peer Reviewed / Open Access
• [Journal Article] X-ray spectra of Sgr A East and diffuse X-raybackground near the Galactic center (2019)
  • Author(s): A. Ono, H. Uchiyama, S. Yamauchi, M. Nobukawa, K. K. Nobukawa, K. Koyama
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 印刷中
  • Peer Reviewed / Open Access
• [Journal Article] New scenario of plasma evolution in IC443 (2019)
  • Author(s): Arisa Hirayama; Shigeo Yamauchi; Kumiko K Nobukawa; Masayoshi Nobukawa; Katsuji Koyama
  • Journal Title: Publications of Astronomical Society of Japan Volume: 71 Issue: 2
  • DOI: 10.1093/pasj/psy153
  • Peer Reviewed / Open Access
• [Journal Article] Discovery of 6.4 keV line and soft X-ray emissions from G323.7-1.0 with Suzaku (2018)
  • Author(s): Saji, Shigetaka; Matsumoto, Hironori; Nobukawa, Masayoshi; Nobukawa, Kumiko K.; Uchiyama, Hideki; Yamauchi, Shigeo; Koyama, Katsuji
  • Journal Title: Publications of the Astronomical Society of Japan Volume: Advance access Issue: 2 Pages: 1-10
  • DOI: 10.1093/pasj/psx158
  • Peer Reviewed / Open Access
• [Journal Article] Origin of the low-temperature plasma in the Galactic center X-ray emission (2018)
  • Author(s): Yamauchi, Shigeo; Shimizu, Miku; Nobukawa, Masayoshi; Nobukawa, Kumiko K.; Uchiyama, Hideki; Koyama, Katsuji
  • Journal Title: Publications of Astronomical Society of Japan Volume: 70 Issue: 4
  • DOI: 10.1093/pasj/psy077
  • Peer Reviewed / Open Access
• [Journal Article] In-orbit performance of the soft X-ray imaging system aboard Hitomi (ASTRO-H) (2018)
  • Author(s): Nakajima Hiroshi, Bamba Aya et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 21-21
  • DOI: 10.1093/pasj/psx116
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hitomi observations of the LMC SNR N 132D: Highly redshifted X-ray emission from iron ejecta (2018)
  • Author(s): Hitomi collaboration, A. Bamba, et al.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 70 Issue: 2 Pages: 16-16
  • DOI: 10.1093/pasj/psx151
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] First discovery of iron line emission generated by low-energy cosmic rays (2018)
  • Author(s): K. K. Nobukawa, M. Nobukawa, S. Yamauchi, H. Uchiyama, K. Koyama
  • Journal Title: Proceedings of 35th International Cosmic Ray Conference Volume: - Pages: 687-687
  • Open Access
• [Journal Article] Soft X-ray Imager aboard Hitomi (ASTRO-H) (2018)
  • Author(s): Tanaka Takaaki、Uchida Hiroyuki、Nakajima Hiroshi、Tsunemi Hiroshi、Hayashida Kiyoshi、Tsuru Takeshi Go、Dotani Tadayasu
  • Journal Title: Journal of Astronomical Telescopes, Instruments, and Systems Volume: 4 Issue: 01 Pages: 1-1
  • DOI: 10.1117/1.jatis.4.1.011211
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Transition from Young to Middle-aged Supernova Remnants: Thermal and Nonthermal Aspects of SNR N132D (2018)
  • Author(s): Bamba Aya、Ohira Yutaka、Yamazaki Ryo、Sawada Makoto、Terada Yukikatsu、Koyama Katsuji、Miller Eric D.、Yamaguchi Hiroya、Katsuda Satoru、Nobukawa Masayoshi、Nobukawa Kumiko K.
  • Journal Title: The Astrophysical Journal Volume: 854 Issue: 1 Pages: 71-71
  • DOI: 10.3847/1538-4357/aaa5a0
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Evidence for a Neutral Iron Line Generated by MeV Protons from Supernova Remnants Interacting with Molecular Clouds (2018)
  • Author(s): Nobukawa, Kumiko K.; Nobukawa, Masayoshi; Koyama, Katsuji; Yamauchi, Shigeo; Uchiyama, Hideki; Okon, Hiromichi; Tanaka, Takaaki; Uchida, Hiroyuki; Tsuru, Takeshi G.
  • Journal Title: The Astrophysical Journal Volume: 854 Issue: 2 Pages: 1-10
  • DOI: 10.3847/1538-4357/aaa8dc
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Localized recombining plasma in G166.0+4.3: A supernova remnant with an unusual morphology (2017)
  • Author(s): H. Matsumura, H. Uchida, T. Tanaka, T. G. Tsuru, M. Nobukawa, K. K. Nobukawa and M. Itou
  • Journal Title: Publication of the Astronomical Society of Japan Volume: 69 Issue: 2 Pages: 30-37
  • DOI: 10.1093/pasj/psx001
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Modeling the spectral response for the soft X-ray imager onboard the ASTRO-H satellite (2016)
  • Author(s): Shota Inoue, Kiyoshi Hayashida, Shuhei Katada, Hiroshi Nakajima, Ryo Nagino, Naohisa Anabuki, Hiroshi Tsunemi, and Shutaro Ueda, et al.
  • Journal Title: Nuclear Instruments and Methods in Physics Research Section A Volume: 00 Pages: 1-5
  • DOI: 10.1016/j.nima.2016.03.071
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Scale heights and equivalent widths of the iron K-shell lines in the Galactic diffuse X-ray emission (2016)
  • Author(s): Yamauchi, S., Nobukawa, K. K., Nobukawa, M., Uchiyama, H., Koyama, K.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 68 Issue: 4 Pages: 59-59
  • DOI: 10.1093/pasj/psw057
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Origin of the Galactic Diffuse X-ray Emission: Iron K-shell Line Diagnostics (2016)
  • Author(s): M. Nobukawa, H. Uchiyama, K. K. Nobukawa, S. Yamauchi, K. Koyama
  • Journal Title: The Astrophysical Journal Volume: 印刷中
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] 低エネルギー宇宙線で輝くX線の天の川―「すざく」の銀河面観測が明らかにした新事実 (2016)
  • Author(s): 信川 久実子
  • Journal Title: 天文月報 Volume: 109 Pages: 773-779
  • Open Access
• [Journal Article] Recombining plasma in the remnant of a core-collapsed supernova, Kes 17 (2015)
  • Author(s): Washino, Ryosaku; Uchida, Hiroyuki; Nobukawa, Masayoshi; Tsuru, Takeshi Go; Tanaka, Takaaki; Kawabata Nobukawa, Kumiko; Koyama, Katsuji
  • Journal Title: PASJ Volume: 67 Issue: SP1 Pages: 7-7
  • DOI: 10.1093/pasj/psv095
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] 硬X線で探る星形成領域 (2020)
  • Author(s): 信川 久実子
  • Organizer: 高感度・広帯域X線天文衛星FORCEで探る高エネルギー宇宙
• [Presentation] 30 Doradus複合領域における中性鉄輝線の調査（2） (2020)
  • Author(s): 信川 久実子
  • Organizer: 日本天文学会2020年春季年会
• [Presentation] Measurements of low-energy cosmic rays (2019)
  • Author(s): Kumiko Nobukawa
  • Organizer: GCWS2019: New Horizons in Galactic Center Astronomy and Beyond
  • Int'l Joint Research / Invited
• [Presentation] MeV宇宙線の研究とMeVガンマ線との関連 (2019)
  • Author(s): 信川 久実子
  • Organizer: 第二回MeVガンマ線天文学研究会
  • Invited
• [Presentation] 30 Doradus複合領域における中性鉄輝線の調査 (2019)
  • Author(s): 信川 久実子
  • Organizer: 日本天文学会2019年秋季年会
• [Presentation] Low-energy cosmic rays in supernova remnants interacting with molecular clouds, (2019)
  • Author(s): Kumiko Nobukawa
  • Organizer: Multifrequency Behaviour of High Energy Cosmic Sources - XIII
  • Int'l Joint Research / Invited
• [Presentation] 中性鉄輝線で探る超新星残骸における低エネルギー宇宙線 (2019)
  • Author(s): 信川久実子
  • Organizer: 第18回高宇連研究会
• [Presentation] X線分光撮像衛星(XRISM)搭載Xtend用試作miniCCDにおけるCTIモデル (2019)
  • Author(s): 信川久実子
  • Organizer: 日本天文学会2019年春季年会
• [Presentation] Observations of neutral iron line in supernova remnants and implications for low-energy cosmic rays (2018)
  • Author(s): Kumiko Nobukawa
  • Organizer: SNR workshop 2018
• [Presentation] 6.4 keV鉄輝線を用いた超新星残骸におけるMeV宇宙線の測定 (2018)
  • Author(s): 信川久実子
  • Organizer: 日本天文学会2018年秋季年会
• [Presentation] Measurement of low-energy cosmic rays in Supernova remnants via neutral iron line (2018)
  • Author(s): Kumiko Nobukawa
  • Organizer: 42nd COSPAR Scientific Assembly
• [Presentation] Measurement of low-energy cosmic rays via the neutral iron line (2018)
  • Author(s): Kumiko Nobukawa
  • Organizer: 26th Extended European Cosmic Ray Symposium and 35th Russian Cosmic Ray Conference
  • Int'l Joint Research / Invited
• [Presentation] X線天文衛星「ひとみ」による超新星残骸N132Dの観測 (2018)
  • Author(s): 信川久実子
  • Organizer: 第17回高宇連研究会
  • Invited
• [Presentation] MAXI J1421-613周辺からのX線円環放射の発見 (2018)
  • Author(s): 信川久実子
  • Organizer: 日本天文学会2018年春季年会
• [Presentation] 分子雲と相互作用している超新星残骸における宇宙線起源の中性鉄輝線探査 (2017)
  • Author(s): 信川久実子
  • Organizer: 日本天文学会2017年秋季年会
• [Presentation] Low-Energy Cosmic Rays from Supernova Remnants (2017)
  • Author(s): Kumiko K. Nobukawa
  • Organizer: SNR workshop 2017
  • Int'l Joint Research / Invited
• [Presentation] 銀河リッジX線放射の中性鉄輝線における低エネルギー宇宙線の寄与 (2017)
  • Author(s): 信川久実子
  • Organizer: 天の川銀河研究会2017
• [Presentation] First discovery of iron line emission generated by low-energy cosmic rays (2017)
  • Author(s): Kumiko K. Nobukawa
  • Organizer: 35th International Cosmic Ray Conference