ハーシェルとあかり衛星観測に基づく近傍銀河中のダスト変成の研究

2014 Fiscal Year Annual Research Report

• Project/Area Number: 23244021
• Research Institution: The University of Tokyo
• Principal Investigator: 尾中 敬 東京大学, 理学(系)研究科(研究院), 教授 (30143358)
• Co-Investigator(Kenkyū-buntansha): 金田 英宏 名古屋大学, 理学(系)研究科(研究院), 教授 (30301724)
• Project Period (FY): 2011-04-01 – 2016-03-31
• Keywords: 宇宙物理学 / 光学赤外線天文学 / 赤外線衛星観測 / 星間物理 / 物質循環

Outline of Annual Research Achievements

ハーシェル衛星の観測で取得した竜骨座星生成領域の遠赤外線分光観測データの整約と解析を詳細に進めた。特に波長により空間分解能が変化することを考慮した新しい整約手法を適用し、最大限に空間分解能を保持した一酸化炭素の各遷移線のマップを求めた。この結果、観測領域の端に位置する分子雲側に特徴的な穴の構造が見られることが初めて分かった。この領域には新たに星が生成されている証拠があり、星生成活動との関連が示唆される。またPACSの分光データも同様に解析し、光解離領域から生じる主要な禁制線[OIII], [NIII], [CII], [NII], [OI], [CI]の強度マップを作成した。さらに同じ領域を観測したスピッツアー衛星による中間線スペクトルおよびより広い領域の「あかり」及びMSXのサーベイデータを用い、22ミクロンにみられる特異なダストバンドの性質の解明を進めた。「あかり」の18ミクロンとMSXの21ミクロンは非常によく一致し、「あかり」の強度較正が確認された。また、この2つのバンドと９ミクロン及びハーシェルの遠赤外線のデータから得られるSEDから22ミクロンバンドが定量的に評価できることを見出した。22ミクロンバンドが強い領域では通常のダストモデルでは説明できないSEDを示すこともわかり、新たな組成のダストの必要性が明確に示された。ガスのデータから単純な輻射輸送のモデルを用い物理状態の推定を行い、特殊なダストが生成される領域の条件を検討した。一方、あかり衛星で観測した合体銀河NGC2782の解析を遠赤外線データもとりいれて進め、中間赤外域放射のバンドキャリアと考えられている有機物がやや大きめの炭素質ダストから分解して生成された可能性を示唆する兆候を得、詳細な議論を行った。また同様の兆候を別の衝突銀河であるNGC7727についても見出し、バンドキャリア生成機構の検討を行った。

Research Progress Status

27年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

27年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] IRAP/CNRS/Observatory of Paris(France)
  • Country Name: France
  • Counterpart Institution: IRAP/CNRS/Observatory of Paris
• [Int'l Joint Research] Tezpur University(India)
  • Country Name: India
  • Counterpart Institution: Tezpur University
• [Journal Article] Deuterated Polycyclic Aromatic Hydrocarbons: Revisited (2016)
  • Author(s): Doney, K., D., Candian, A., Mori, T., Onaka, T., and Tielens, A. G. G. M.,
  • Journal Title: Astronomy and Astrophysics Volume: 586 Pages: A65 (10pp)
  • DOI: 10.1051/0004-6361/201526809
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The mixed aliphatic/aromatic composition of evaporating very small grains in NGC 7023 viewed by the 3.4/3.3 micron meter ratio (2015)
  • Author(s): Pilleri, P., Joblin, C., Boulanger, F., and Onaka, T.
  • Journal Title: Astronomy and Astrophysics Volume: 577 Pages: A16 (8pp)
  • DOI: 10.1051/0004-6361/201425590
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Dust processing in the Carina nebula region (2015)
  • Author(s): Onaka, T., Mori, T. I., and Okada, Y.
  • Journal Title: Planetary and Space Science Volume: 116 Pages: 84--91
  • DOI: 10.1016/j.pss.2015.03.025
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] A study of iron and dust in the supernova remnant IC443 (2015)
  • Author(s): Kokusho, T., Nagayama, T., Kaneda, H., Ishihara, D., Lee, H.-G., and Onaka, T.
  • Journal Title: Planetary and Space Science Volume: 116 Pages: 92--96
  • DOI: 10.1016/j.pss.2015.04.009
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Systematic Variations in CO2/H2O Ice Abundance Ratios in Nearby Galaxies Found with AKARI Near-Infrared Spectroscopy, (2015)
  • Author(s): Yamagishi, M., Kaneda, H., Ishiara, D., Oyabu, S., Onaka, T. Shimonishi, T., and Suzuki, T.
  • Journal Title: Astrophysical Journal Volume: 807 Pages: 29 (8pp)
  • DOI: 10.1088/0004-637X/807/1/29
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Theoretical study of deuteronated PAHs as carriers for IR emission features in the ISM (2015)
  • Author(s): Buragohain, M., Pathak, A., Sarre, P., Onaka, T., and Sakon, I.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 454 Pages: 193--204
  • DOI: 10.1093/mnras/stv1946
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Search for the Infrared Emission Features from Deuterated Interstellar Polycyclic Aromatic Hydrocarbons (2014)
  • Author(s): Onaka, T., Mori, T. I., Sakon, I., Ohsawa, R., Kaneda, H., Okada, Y., and Tanaka, M.
  • Journal Title: Astrophysical Journal Volume: 780 Pages: 114 (9pp)
  • DOI: 10.1088/0004-637X/780/2/114
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Observational studies on the near-infrared unidentified emission bands in Galactic HII regions (2014)
  • Author(s): Mori, T. I., Onaka, T., Sakon, I., Ishihara, D., Shimonishi, T., Ohsawa, R., Bell, A. C.
  • Journal Title: Astrophysical Journal Volume: 787 Pages: 53 (12pp)
  • DOI: 10.1088/0004-637X/784/1/53
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] AKARI observations of interstellar dust grains in our Galaxy and nearby galaxies (2014)
  • Author(s): Kaneda, H., Ishihara, D., Kobata, J., Kondo, T., Oyabu, S., Yamada, R., Yamaguchi, M., Onaka, T., and Suzuki, T.
  • Journal Title: Planetary and Space Science Volume: 100 Pages: 6--11
  • DOI: 10.1016/j.pss.2014.01.017
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Organic dust in galaxies (2015)
  • Author(s): Onaka, T.
  • Organizer: The 11th Pacific Rim Conference on Stellar Astrophysics, Physics and Chemistry of the Late Stages of Stellar Evolution
  • Place of Presentation: Hong Kong, PR China,
  • Year and Date: 2015-12-14 – 2015-12-17
  • Int'l Joint Research / Invited
• [Presentation] Interstellar ices as revealed by AKARI near-infrared spectroscopy (2015)
  • Author(s): Onaka, T., Mori, T. I., Sakon, I., and Shimonishi, T.
  • Organizer: Cosmic Dust VIII
  • Place of Presentation: 千葉工業大学スカイツリータウンキャンパス（東京都墨田区）
  • Year and Date: 2015-08-17 – 2015-08-21
  • Int'l Joint Research
• [Presentation] Mid-infrared vibrational study of substituted PAHs: implications to aromatic infrared bands (2015)
  • Author(s): Buragohain, M., Pathak, M., Sarre, P., Onaka, T., and Sakon, I.
  • Organizer: Cosmic Dust VIII
  • Place of Presentation: 千葉工業大学スカイツリータウンキャンパス（東京都墨田区）
  • Year and Date: 2015-08-17 – 2015-08-21
  • Int'l Joint Research
• [Presentation] AKARI observations of dust processing in merger galaxies: NGC2782 and NGC7727 (2015)
  • Author(s): Onaka, T., Nakamura, T., Sakon, I., Ohsawa, R., Mori, T., Wu, R., Kaneda, H.
  • Organizer: IAU Symposium 315, From Interstellar Clouds to Star-forming Galaxies: Universal Processes?
  • Place of Presentation: Honolulu, Hawaii, U.S.A.
  • Year and Date: 2015-08-03 – 2015-08-07
  • Int'l Joint Research
• [Presentation] Spatially resolved physical conditions of molecular gas: a zoom-in from circumnuclear region of M83 to Carina nebula (2015)
  • Author(s): Wu, R., Madden, S., Galliano, F., Wilson, C., Onaka, C., Nakamura, T.
  • Organizer: IAU Symposium 315, From Interstellar Clouds to Star-forming Galaxies: Universal Processes?
  • Place of Presentation: Honolulu, Hawaii, U.S.A.
  • Year and Date: 2015-08-03 – 2015-08-07
  • Int'l Joint Research
• [Presentation] AKARI near-infrared spectroscopy of interstellar ices (2015)
  • Author(s): Onaka, T., Mori, T., Sakon, I., Shimonishi, T.
  • Organizer: Focused Meeting 12, Bridging Laboratory Astrophysics and Astronomy, IAU General Assembly
  • Place of Presentation: Honolulu, Hawaii, U.S.A.
  • Year and Date: 2015-08-03 – 2015-08-05
  • Int'l Joint Research
• [Presentation] Near-infrared spectroscopy of galactic PDRs with AKARI (2015)
  • Author(s): Onaka, T., Mori, T. I., Sakon, I., Bell, A., Oshawa, R., Shimonishi, T., and Ishihara, D.
  • Organizer: 30 years of PhotoDissociation Regions, A symposium to honor David Hollenbach's lifetime in science
  • Place of Presentation: Asilomar, California, U.S.A.
  • Year and Date: 2015-06-28 – 2015-07-03
  • Int'l Joint Research
• [Presentation] Dust processing in the interstellar medium (2014)
  • Author(s): Onaka, T. Okada, Y., Mori, T. I., Nakamura, T., Hammonds, M., Wu, R., Sakon, I., and Ishihara, D.
  • Organizer: International Conference on Interstellar Dust, Molecules and Chemistry 2014,
  • Place of Presentation: Tezpur, India
  • Year and Date: 2014-12-15 – 2014-12-18
  • Int'l Joint Research / Invited
• [Presentation] Search for deuterated PAHs in the ISM from observations and experiments (2014)
  • Author(s): Mori, T. I., Sakon, I., Onaka, T., Hammonds, M., Sato, K., Ohsawa, R., Takahata, N., Sano, Y., Kimura, S., and Wada, S.
  • Organizer: International Conference on Interstellar Dust, Molecules and Chemistry 2014
  • Place of Presentation: Tezpur, India
  • Year and Date: 2014-12-15 – 2014-12-18
  • Invited
• [Presentation] Lifecycle of dust grains in the interstellar medium (2014)
  • Author(s): Onaka, T., Mori, T. I., and Okada, Y.
  • Organizer: Cosmic Dust VII
  • Place of Presentation: 大阪産業大学梅田サテライトキャンパス（大阪府大阪市）
  • Year and Date: 2014-08-04 – 2014-08-08
  • Int'l Joint Research / Invited
• [Presentation] Processing of the Interstellar Medium as Divulged by AKARI (2014)
  • Author(s): Onaka, T., Mori, T. I., Ohsawa, R., Sakon, I., Bell, A.C., Hammonds, M., Shimonishi, T., Ishihara, D., Kaneda, H., Okada, Y., and Tanaka, M.
  • Organizer: THE UNIVERSE IN THE LIGHT OF AKARI and Synergy with future Large Space Telescopes
  • Place of Presentation: Oxford, U.K.
  • Year and Date: 2014-07-09 – 2014-07-11
  • Int'l Joint Research / Invited