高感度軟ガンマ線観測による重力波天体キロノバでの重元素合成の探査

• Project Area: New development in astrophysics through multimessenger observations of gravitational wave sources
• Project/Area Number: 15H00773
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Saitama University
• Principal Investigator: 寺田 幸功 埼玉大学, 理工学研究科, 准教授 (90373331)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2016: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 中性子星連星合体 / 宇宙ガンマ線観測 / 重元素合成 / ASTRO-H 「ひとみ」衛星 / 宇宙物理学 / Ｘ線天文学 / ガンマ線放射推定 / ASTRO-H「ひとみ」衛星

Outline of Annual Research Achievements

本研究では、「我々はどこからくるのか？」という根本的な科学的問いに答えるべく、宇宙における重元素合成の現場を観測的に捉える事を最終目的に、重力波天体の候補である連星中性子星で合成された核ガンマ線の検出を狙った。
平成２７年度に、r-process 新星とされる連星中性子星で合成された重元素からのガンマ線放射の推定が完了し、300 キロ電子ボルト以上の軟ガンマ線帯域が唯一の核ガンマ線を検出できる帯域であることが明確となったため、我々は、当時、該当する帯域で最高感度を誇ると予想されていた ASTRO-H 「ひとみ」衛星に搭載された軟ガンマ線検出器での観測計画を整えた。しかし、平成２８年度初め、事故により「ひとみ」衛星の運用は中断されたため、r-process 新星である連星中性子星の観測は実施できなかった。
平成２８年度は、「ひとみ」衛星が軌道上で稼働して得た１ヶ月のデータを精査し、搭載機器の較正精度をあげ、NASA・JAXAの研究者らと共に研究代表者が中心となって、初期運用の特殊な観測モードに対応したデータプロセスを３段階にわけ実施し、ほぼ完了するまで至った。本研究課題では、「ひとみ」搭載の軟ガンマ線検出器や硬エックス線検出器のバックグラウンドを確認し、将来の軟ガンマ線検出器を高感度化するための基礎研究も行い、Geant4 モンテカルロ数値計算を用いた概念設計等も行った。「ひとみ」亡き今、連星中性子星からの核ガンマ線が狙える高感度な軟ガンマ線検出器の計画は15年以上先になってしまったが、将来実現すべき高感度な軟ガンマ線検出器の開発にむけた研究の指針を示すことはできた。

Research Progress Status

28年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

28年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] NASA/GSFC/Massachusetts Institute of Technology/Stanford University(米国)
• [Int'l Joint Research] NASA Goddard Space Flight Center/Massachusetts Institute of Technology(米国)
• [Int'l Joint Research] The Hebrew University of Jerusalem(イスラエル)
• [Journal Article] The quiescent intracluster medium in the core of the Perseus cluster (2016)
  • Author(s): Hitomi Collaboration et al.
  • Journal Title: Nature Volume: 535 Issue: 7610 Pages: 117-121
  • DOI: 10.1038/nature18627
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hitomi Constraints on the 3.5 keV Line in the Perseus Galaxy Cluster (2016)
  • Author(s): Aharonian, F. A., Akamatsu, H, Terada, Y. et al (Hitomi collaboration)
  • Journal Title: The Astrophysical Journal Letters Volume: 837 Issue: 1 Pages: 15-23
  • DOI: 10.3847/2041-8213/aa61fa
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Measurements of the Soft Gamma-Ray Emission from SN2014J with Suzaku (2016)
  • Author(s): Terada, Y., Maeda, K., Fukazawa, Y., Bamba, A., Ueda, Y., Katsuda, S., Enoto, T., Takahashi, T., Tamagawa, T., Roepke, F. K., Summa, A., Diehl, R.
  • Journal Title: The Astrophysical Journal Volume: 823 Issue: 1 Pages: 43-43
  • DOI: 10.3847/0004-637x/823/1/43
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] New identification of the mixed-morphology supernova remnant G298.6-0.0 with possible gamma-ray association (2016)
  • Author(s): Bamba, Aya; Sawada, Makoto; Nakano, Yuto; Terada, Yukikatsu; Hewitt, John; Petre, Robert; Angelini, Lorella
  • Journal Title: Publications of the Astronomical Society of Japan Volume: not assigned Issue: SP1 Pages: 1-7
  • DOI: 10.1093/pasj/psv096
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Suzaku observations of the hard X-ray spectrum of Vela Jr. (SNR RX J0852.0-4622) (2016)
  • Author(s): Takeda, S., Bamba, A., Terada, Y., Tashiro, M. S., Katsuda, S., Yamazaki, R.,Ohira, Y., Iwakiri, W.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 68 Issue: SP1
  • DOI: 10.1093/pasj/psw036
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Progenitors of type Ia supernovae (2016)
  • Author(s): Maeda, Keiichi, and Terada, Yukikatsu
  • Journal Title: International Journal of Modern Physics D Volume: 25 Issue: 10 Pages: 1630024-1630024
  • DOI: 10.1142/s021827181630024x
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Suzaku Wide-band All-sky Monitor measurements of duration distributions of gamma-ray bursts (2016)
  • Author(s): Norisuke Ohmori
  • Journal Title: Publication of the Astronomical Society of Japan Volume: 未定 Issue: SP1 Pages: 20-30
  • DOI: 10.1093/pasj/psw009
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Two Distinct-absorption X-Ray Components from Type IIn Supernovae: Evidence for Asphericity in the Circumstellar Medium (2016)
  • Author(s): Katsuda, S., Maeda, K., Bamba, A., Terada, Y., Fukazawa, Y., Kawabata, K., Ohno, M.,Sugawara, Y., Tsuboi, Y.,Immler, S.
  • Journal Title: The Astrophysical Journal, Volume: 832 Issue: 2 Pages: 194-194
  • DOI: 10.3847/0004-637x/832/2/194
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Radioactive decay products in neutron star merger ejecta: heating efficiency and γ-ray emission (2016)
  • Author(s): Hotokezaka, K., Wanajo, S., Tanaka, M., Bamba, A., Terada, Y., Piran, T.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 459 Issue: 1 Pages: 35-43
  • DOI: 10.1093/mnras/stw404
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Presentation] Summary of Hitomi Timing calibration (2017)
  • Author(s): Terada Yukikatsu et al.
  • Organizer: the 12th International Astronomical Consortium for High Energy Calibration meeting
  • Place of Presentation: UCLA Lake Arrowhead Conference Center, USA
  • Year and Date: 2017-03-27
  • Int'l Joint Research / Invited
• [Presentation] Status of the X-ray Astronomy Recovery Mission (2017)
  • Author(s): Terada Yukikatsu, Tashiro Makoto et al.
  • Organizer: the 12th International Astronomical Consortium for High Energy Calibration meeting
  • Place of Presentation: UCLA Lake Arrowhead Conference Center, USA
  • Year and Date: 2017-03-27
  • Int'l Joint Research / Invited
• [Presentation] Short burst from AXP 1E1547.0-5408 with Suzaku HXD WAM (2017)
  • Author(s): 寺田幸功
  • Organizer: 第四回「すざく」HXD WAM 会議
  • Place of Presentation: 名古屋大学東山キャンパス（愛知県名古屋市）
  • Year and Date: 2017-03-23
  • Int'l Joint Research / Invited
• [Presentation] Ｘ線天文衛星「ひとみ」と電波の同時観測による「かに星雲」パルサーからのGiant radio pulse のX 線特性 (2017)
  • Author(s): 寺田幸功(埼玉大), 榎戸輝揚(京都大), 小山志勇(宇宙研), 馬場彩(東大), ほか
  • Organizer: 日本天文学会 2017年春季年会
  • Place of Presentation: 九州大学伊都キャンパス（福岡県福岡市）
  • Year and Date: 2017-03-15
• [Presentation] Ia型超新星 SN2014Jの「すざく」sub MeV 観測レビューと将来 MeV観測 (2017)
  • Author(s): Terada Yukikatsu et al.
  • Organizer: 第1回MeVガンマ線天文学研究会
  • Place of Presentation: 京都大学 北部総合教育研究棟 (京都府京都市)
  • Year and Date: 2017-02-27
  • Invited
• [Presentation] Future high-sensitive gamma-ray observations of nucleosynthesis nuclei in neutron star mergers (2016)
  • Author(s): Terada Yukikatsu et al.
  • Organizer: Symposium on "New development in astrophysics through multimessenger observations of gravitational wave sources"
  • Place of Presentation: 京都大学 基礎物理学研究所 (京都府京都市)
  • Year and Date: 2016-12-26
  • Int'l Joint Research
• [Presentation] Soft Gamma-ray Observation of SN2014J with Suzaku (2016)
  • Author(s): Terada Yukikatsu
  • Organizer: Nuclei in the Cosmos XIV
  • Place of Presentation: 朱鷺メッセ 新潟コンベンションセンター(新潟県新潟市)
  • Year and Date: 2016-06-19
  • Int'l Joint Research
• [Presentation] Hitomi satellite, SXS simulators (2016)
  • Author(s): Terada Yukikatsu
  • Organizer: Workshop "High-resolution X-ray spectroscopic software and tools"
  • Place of Presentation: ESA-ESAC, Villanueva de la Canada, Madrid, Spain
  • Year and Date: 2016-05-12
  • Int'l Joint Research / Invited
• [Presentation] MeV Gamma-ray Studies of Neutron Star Merger (2016)
  • Author(s): Terada Yukikatsu
  • Organizer: Innovative Area on Multi-messenger Study of Gravitational Wave Sources
  • Place of Presentation: ICRC, Univ of Tokyo
  • Year and Date: 2016-02-18
  • Int'l Joint Research
• [Presentation] Review on the soft Gamma-ray observational studies of Supernovae as Nucleaosynthesis Sites (2015)
  • Author(s): Terada, Yukikatsu
  • Organizer: the Supernova Remnant workshop, Nagoya
  • Place of Presentation: Nagoya University.
  • Year and Date: 2015-06-18
  • Int'l Joint Research / Invited