A Study of Interstellar Large Organic Molecules Explored with Near-infrared High-resolution Spectroscopy

• Project/Area Number: 16K17669
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan (2018-2019); Kyoto Sangyo University (2016-2017)
• Principal Investigator: Hamano Satoshi 国立天文台, TMTプロジェクト, 特任研究員 (70756270)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
• Keywords: 星間有機分子 / 赤外線高分散分光 / フラーレン / 星間物質 / 星間巨大有機分子 / 近赤外線 / 高分散分光 / 量子化学

Outline of Final Research Achievements

In order to identify of the carrier molecules of diffuse interstellar bands (DIBs), which are expected to be an important tool to investigate the interstellar organic molecules, I conducted a observational study of DIBs in the near-infrared (NIR) wavelength range, in which the DIBs have not been fully investigated. First, I developed a data reduction pipeline software for the NIR high-resolution spectrograph WINERED, which was mainly used in this study. I collected the near-infrared spectra of a lot of targets, and investigated the environmental dependence of NIR DIBs and its intrinsic profiles. As a result, I succeeded to reveal the properties of the carriers of NIR DIBs. In addition, I also succeeded to detect the NIR absorption bands originated from interstellar C2 and CN molecules for the first time.

Academic Significance and Societal Importance of the Research Achievements

宇宙における生命の発生過程や惑星系の素となるダストの性質を調べる上で、星間ガス雲中における複雑な有機分子の反応過程や分布は重要である。本研究では、フラーレンやPAHといった巨大な有機分子を調べる道具として期待されているDIBの分子同定に向けて重要な手がかりをいくつか得ることに成功した。本研究を足がかりとしてDIBの同定が成功すれば宇宙における有機分子を探る新たなツールを手に入れることとなり、宇宙化学、宇宙生物学の大きな進展が期待される。

Research Products

• [Journal Article] First Detection of A-X (0,0) Bands of Interstellar C2 and CN (2019)
  • Author(s): Hamano Satoshi、Kawakita Hideyo、Kobayashi Naoto、Takenaka Keiichi、Ikeda Yuji、Matsunaga Noriyuki、Kondo Sohei、Sameshima Hiroaki、Fukue Kei、Yasui Chikako、Mizumoto Misaki、Otsubo Shogo、Watase Ayaka、Yoshikawa Tomohiro、Kobayashi Hitomi
  • Journal Title: The Astrophysical Journal Volume: 881 Issue: 2 Pages: 143-143
  • DOI: 10.3847/1538-4357/ab2e0f
  • Peer Reviewed
• [Journal Article] A Survey of Near-infrared Diffuse Interstellar Bands (2018)
  • Author(s): Hamano Satoshi, Kobayashi Naoto, Kawakita Hideyo, Ikeda Yuji, Kondo Sohei, Sameshima Hiroaki, Arai Akira, Matsunaga Noriyuki, Yasui Chikako, Mizumoto Misaki, Fukue Kei, Izumi Natsuko, Otsubo Shogo, Takenaka Keiichi
  • Journal Title: Bulletin de la Society Royale des Sciences de Liege, in Proceedings of the First Belgo-Indian Network for Astronomy & Astrophysics (BINA) workshop Volume: 87 Pages: 276-280
  • DOI: 10.25518/0037-9565.7702
  • Peer Reviewed / Open Access
• [Journal Article] Near Infrared Diffuse Interstellar Bands Toward the Cygnus OB2 Association (2016)
  • Author(s): Hamano, S., Kobayashi, N., Kondo, S., Sameshima, H., Nakanishi, K., Ikeda, Y., Yasui, C., Mizumoto, M., Matsunaga, N., Fukue, K., Yamamoto, R., Izumi, N., Mito, H., Nakaoka, T., Kawanishi, T., Kitano, A., Otsubo, S., Kinoshita, M., and Kawakita, H.
  • Journal Title: The Astrophysical Journal Volume: 821 Issue: 1 Pages: 42-53
  • DOI: 10.3847/0004-637x/821/1/42
  • Peer Reviewed
• [Presentation] 近赤外線高分散分光器WINERED: データ解析パイプラインの開発 (2019)
  • Author(s): 濱野哲史, 近藤荘平, 鮫島寛明, 福江慧, 新井彰, 河北秀世, 大坪翔悟, 竹中慶一, 渡瀬彩華, 池田優二, 小林尚人, 松永典之, 安井千香子
  • Organizer: 日本天文学会2019年春季年会
• [Presentation] Diffuse Interstellar Bands: Cosmic Shadow of Interstellar Molecules (2018)
  • Author(s): 濱野哲史
  • Organizer: Cosmic Shadow 2018 - クェーサー吸収線系でみる宇宙-
• [Presentation] NIR Diffuse Interstellar Bands Survey with WINERED (2018)
  • Author(s): 濱野哲史
  • Organizer: WINERED研究会2018
• [Presentation] WINERED Pipeline: Current status, Problems & Upcoming Updates (2018)
  • Author(s): 濱野哲史
  • Organizer: WINERED研究会2018
• [Presentation] Magellanic Clouds with Magellan: Complex Molecules in Low Metallicity Environment (2018)
  • Author(s): 濱野哲史
  • Organizer: WINERED研究会2018
• [Presentation] DIB λ 10697のキャリアへの制限 (2018)
  • Author(s): 竹中慶一, 濱野哲史, 河北秀世, 小林尚人
  • Organizer: WINERED研究会2018
• [Presentation] A Survey of Near-infrared Diffuse Interstellar Bands (2017)
  • Author(s): Hamano Satoshi
  • Organizer: IAU Symposium 332: Astrochemistry VII - Through the Cosmos from Galaxies to Planets
  • Place of Presentation: Puerto Varas, Chile
  • Year and Date: 2017-03-20
  • Int'l Joint Research
• [Presentation] Survey of Near-infrared Diffuse Interstellar Bands (2017)
  • Author(s): Satoshi Hamano
  • Organizer: Fullerenes in Space Workshop
  • Int'l Joint Research
• [Presentation] Near-infrared spectroscopic study of interstellar free radicals (2017)
  • Author(s): Satoshi Hamano, Naoto Kobayashi, Hideyo Kawakita, Keiichi Takenaka
  • Organizer: 34th International Workshop of Free Radicals
  • Int'l Joint Research
• [Presentation] 近赤外線高分散分光器WINERED: C2, CN 分子バンドの検出 (2017)
  • Author(s): 濱野哲史, 河北秀世, 竹中慶一, 池田優二, 近藤荘平, 鮫島寛明, 福江慧, 新井彰, 大坪翔悟, 渡瀬彩華, 小林尚人, 松永典之, 安井千香子
  • Organizer: 日本天文学会2017年度秋季年会
• [Presentation] 近赤外線高分散分光器WINERED: DIBλ10697のキャリア分子への制限 (2017)
  • Author(s): 竹中慶一, 濱野哲史, 河北秀世, 池田優二, 近藤荘平, 鮫島寛明, 福江慧, 小林尚人, 松永 典之, 安井千香子
  • Organizer: 日本天文学会2017年度秋季年会
• [Presentation] A Survey of Near-infrared Diffuse Interstellar Bands (2016)
  • Author(s): Hamano Satoshi
  • Organizer: 1st BINA Workshop
  • Place of Presentation: Nainital, India
  • Year and Date: 2016-11-15
  • Int'l Joint Research
• [Presentation] A Survey of Near-infrared Diffuse Interstellar Bands (2016)
  • Author(s): Hamano Satoshi
  • Organizer: ISM2016
  • Place of Presentation: 北海道大学（北海道札幌市）
  • Year and Date: 2016-10-19
  • Int'l Joint Research
• [Presentation] A Survey of Near-infrared Diffuse Interstellar Bands (2016)
  • Author(s): Hamano Satoshi
  • Organizer: 近赤外線高分散分光観測で探る恒星物理
  • Place of Presentation: 東京大学（東京都文京区）
  • Year and Date: 2016-10-05
  • Int'l Joint Research
• [Presentation] 近赤外線高分散分光器 WINERED による微弱な DIB の探査 (2016)
  • Author(s): 濱野哲史
  • Organizer: 日本天文学会2016年秋季年会
  • Place of Presentation: 愛媛大学（愛媛県松山市）
  • Year and Date: 2016-09-14