ALMA Studies of the Dynamics of Low-Metallicity Star Forming Regions

• Project Area: A Paradigm Shift by a New Integrated Theory of Star Formation: Exploring the Expanding Frontier of Habitable Planetary Systems in Our Galaxy
• Project/Area Number: 21H00058
• 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: Tokyo Institute of Technology
• Principal Investigator: 田中 圭 東京工業大学, 理学院, 助教 (20634455)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2022: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000); Fiscal Year 2021: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
• Keywords: ALMA / 大小マゼラン雲 / 大質量星形成 / 星形成 / 低金属量 / 電波天文学 / 理論天文学

Outline of Research at the Start

星々の誕生過程は宇宙史を通じて普遍的だったのでしょうか？それとも金属量が増加することで、そのダイナミクスは変化してきたのでしょうか？初期宇宙のような低金属量環境での星形成過程, 特に円盤形成やアウトフロー噴出といった原始星ダイナミクスについての観測的研究はまだ全くと言っていいほどなされていないのが現状です。そこで本研究ではALMA望遠鏡による低金属量近傍銀河・大小マゼラン雲における原始星サーベイ観測を主軸に、理論研究を組み合わせることで「星形成過程の金属量依存性」を明らかにすることを目指します。

Outline of Annual Research Achievements

本研究では観測と理論の両面から星形成の普遍性と多様性の調査を行っている。観測面からは、下西准教授, 徳田特任助教, Sewilo研究員等との国際協力のもと、大小マゼラン雲の大質量原始星に対するALMAサーベイ観測の解析を進めた。特に、小マゼラン雲におけるホットコア初検出を報告する論文が出版され (Shimonishi et al. 2023)、AAS Novaなどでもその成果はハイライトされた。大小マゼラン雲のホットコアでは何故か大型有機分子が枯渇する傾向が明らかとなってきた。大マゼラン雲30天体のHCO+輝線解析からは、特に明るい原始星 (>50,000太陽光度) はハブ・フィラメント系から誕生することを示した (Tokuda et al. 2023)。また系外銀河における水素高次再結合線の初検出も報告した (Sewilo et al. 2023)。さらに、新たな大小マゼラン雲原始星の高分解能ALMA観測データも複数取得することに成功しており、今後、さらなる観測研究における発展が望める。理論面からは昨年度、我々が発見した「小マゼラン雲の弱いCOアウトフロー」について、CO分子の原始星紫外線によって説明できる可能性があることが分かってきた。現在、観測と理論の成果を合わせて論文執筆を進めている (Tanaka et al., in prep.)。本課題研究を通じて、宇宙史を通じた星形成物理と化学の普遍性・多様性の理解が大きく進展したと言える。

Research Progress Status

令和4年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和4年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] コロラド大学ボルダー校/アメリカ国立電波天文台/バージニア大学(米国)
• [Int'l Joint Research] チャルマース工科大学(スウェーデン)
• [Int'l Joint Research] 上海交通大学/Zhejiang Laboratory(中国)
• [Int'l Joint Research] コロラド大学ボルダー校/アメリカ国立電波天文台/バージニア大学(米国)
• [Int'l Joint Research] チャルマース工科大学(スウェーデン)
• [Int'l Joint Research] Zhejiang Laboratory(中国)
• [Int'l Joint Research] ウィーン大学(オーストリア)
• [Journal Article] Astrochemical Diagnostics of the Isolated Massive Protostar G28.20-0.05 (2024)
  • Author(s): Gorai Prasanta、Law Chi-Yan、Tan Jonathan C.、Zhang Yichen、Fedriani Ruben、Tanaka Kei E. I.、Bonfand Melisse、Cosentino Giuliana、Mardones Diego、Beltran Maria T.、Garay Guido
  • Journal Title: The Astrophysical Journal Volume: 960 Issue: 2 Pages: 127-127
  • DOI: 10.3847/1538-4357/ad09bb
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Near-infrared observations of outflows and young stellar objects in the massive star-forming region AFGL 5180 (2024)
  • Author(s): Crowe S.、Fedriani R.、Tan J. C.、Whittle M.、Zhang Y.、Caratti o Garatti A.、Farias J. P.、Gautam A.、Telkamp Z.、Rothberg B.、Grudic M.、Andersen M.、Cosentino G.、Garcia-Lopez R.、Rosero V.、Tanaka K.
  • Journal Title: Astronomy & Astrophysics Volume: 682 Pages: A2-A2
  • DOI: 10.1051/0004-6361/202348094
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Disk Wind Feedback from High-mass Protostars. III. Synthetic CO Line Emission (2024)
  • Author(s): Xu Duo、Tan Jonathan C.、Staff Jan E.、Ramsey Jon P.、Zhang Yichen、Tanaka Kei E. I.
  • Journal Title: The Astrophysical Journal Volume: 966 Issue: 1 Pages: 117-117
  • DOI: 10.3847/1538-4357/ad3211
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Detection of Hot Molecular Cores in the Small Magellanic Cloud (2023)
  • Author(s): Shimonishi Takashi、Tanaka Kei E. I.、Zhang Yichen、Furuya Kenji
  • Journal Title: The Astrophysical Journal Letters Volume: 946 Issue: 2 Pages: L41-L41
  • DOI: 10.3847/2041-8213/acc031
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Disk Wind Feedback from High-mass Protostars. II. The Evolutionary Sequence (2023)
  • Author(s): Staff Jan E.、Tanaka Kei E. I.、Ramsey Jon P.、Zhang Yichen、Tan Jonathan C.
  • Journal Title: The Astrophysical Journal Volume: 947 Issue: 1 Pages: 40-40
  • DOI: 10.3847/1538-4357/acbd47
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Massive Protostellar Disks as a Hot Laboratory of Silicate Grain Evolution (2023)
  • Author(s): Yamamuro Ryota、Tanaka Kei E. I.、Okuzumi Satoshi
  • Journal Title: The Astrophysical Journal Volume: 949 Issue: 1 Pages: 29-29
  • DOI: 10.3847/1538-4357/acc52f
  • Peer Reviewed / Open Access
• [Journal Article] An ALMA Glimpse of Dense Molecular Filaments Associated with High-mass Protostellar Systems in the Large Magellanic Cloud (2023)
  • Author(s): Tokuda Kazuki、Harada Naoto、Tanaka Kei E. I.、Inoue Tsuyoshi、Shimonishi Takashi、Zhang Yichen、Sewilo Marta、Kunitoshi Yuri、Konishi Ayu、Fukui Yasuo、Kawamura Akiko、Onishi Toshikazu、Machida Masahiro N.
  • Journal Title: The Astrophysical Journal Volume: 955 Issue: 1 Pages: 52-52
  • DOI: 10.3847/1538-4357/acefb7
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Chemical Evolution of Some Selected Complex Organic Molecules in Low-mass Star-forming Regions (2023)
  • Author(s): Bhat Bratati、Kar Rumela、Mondal Suman Kumar、Ghosh Rana、Gorai Prasanta、Shimonishi Takashi、Tanaka Kei E. I.、Furuya Kenji、Das Ankan
  • Journal Title: The Astrophysical Journal Volume: 958 Issue: 2 Pages: 111-111
  • DOI: 10.3847/1538-4357/acfc4d
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The Detection of Higher-order Millimeter Hydrogen Recombination Lines in the Large Magellanic Cloud (2023)
  • Author(s): Sewilo Marta、Tokuda Kazuki、Kurtz Stan E.、Charnley Steven B.、Maller Thomas、Wiseman Jennifer、Chen C.-H. Rosie、Indebetouw Remy、Sanchez-Monge Alvaro、Tanaka Kei E. I.、Schilke Peter、Onishi Toshikazu、Harada Naoto
  • Journal Title: The Astrophysical Journal Volume: 959 Issue: 1 Pages: 22-22
  • DOI: 10.3847/1538-4357/acf5ed
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Observational signatures of forming young massive clusters: continuum emission from dense HII regions (2023)
  • Author(s): Inoguchi Mutsuko、Hosokawa Takashi、Fukushima Hajime、Tanaka Kei E I、Yajima Hidenobu、Mineshige Shin
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 527 Issue: 2 Pages: 3612-3623
  • DOI: 10.1093/mnras/stad3297
  • Peer Reviewed / Open Access
• [Journal Article] Salt-bearing Disk Candidates around High-mass Young Stellar Objects (2023)
  • Author(s): Ginsburg Adam、McGuire Brett A.、Sanhueza Patricio、Olguin Fernando、Maud Luke T.、Tanaka Kei E. I.、Zhang Yichen、Beuther Henrik、Indriolo Nick
  • Journal Title: The Astrophysical Journal Volume: 942 Issue: 2 Pages: 66-66
  • DOI: 10.3847/1538-4357/ac9f4a
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Massive Protostellar Disks as a Hot Laboratory of Silicate Grain Evolution (2023)
  • Author(s): Ryota Yamamuro, Kei E. I. Tanaka, Satoshi Okuzumi
  • Journal Title: The Astrophysical Journal Volume: -
  • Peer Reviewed / Open Access
• [Journal Article] Vibrationally Excited Lines of HC3N Associated with the Molecular Disk around the G24.78+0.08 A1 Hypercompact H ii Region (2022)
  • Author(s): Taniguchi Kotomi、Tanaka Kei E. I.、Zhang Yichen、Fedriani Ruben、Tan Jonathan C.、Takakuwa Shigehisa、Nakamura Fumitaka、Saito Masao、Majumdar Liton、Herbst Eric
  • Journal Title: The Astrophysical Journal Volume: 931 Issue: 2 Pages: 99-99
  • DOI: 10.3847/1538-4357/ac69d1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An ALMA Study of the Massive Molecular Clump N159W-North in the Large Magellanic Cloud: A Possible Gas Flow Penetrating One of the Most Massive Protocluster Systems in the Local Group (2022)
  • Author(s): Tokuda Kazuki et al.
  • Journal Title: The Astrophysical Journal Volume: 933 Issue: 1 Pages: 20-20
  • DOI: 10.3847/1538-4357/ac6b3c
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Massive Protostars in a Protocluster - A Multi-scale ALMA View of G35.20-0.74N (2022)
  • Author(s): Zhang Yichen、Tanaka Kei E. I.、Tan Jonathan C.、Yang Yao-Lun、Greco Eva、Beltran Maria T.、Sakai Nami、De Buizer James M.、Rosero Viviana、Fedriani Ruben、Garay Guido
  • Journal Title: The Astrophysical Journal Volume: 936 Issue: 1 Pages: 68-68
  • DOI: 10.3847/1538-4357/ac847f
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The First Detection of a Protostellar CO Outflow in the Small Magellanic Cloud with ALMA (2022)
  • Author(s): Tokuda Kazuki、Zahorecz Sarolta、Kunitoshi Yuri、Higashino Kosuke、Tanaka Kei E. I.、Konishi Ayu、Suzuki Taisei、Kitano Naoya、Harada Naoto、Shimonishi Takashi、Neelamkodan Naslim、Fukui Yasuo、Kawamura Akiko、Onishi Toshikazu、Machida Masahiro N.
  • Journal Title: The Astrophysical Journal Letters Volume: 936 Issue: 1 Pages: L6-L6
  • DOI: 10.3847/2041-8213/ac81c1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Protostellar-disc fragmentation across all metallicities (2022)
  • Author(s): Matsukoba Ryoki、Tanaka Kei E I、Omukai Kazuyuki、Vorobyov Eduard I、Hosokawa Takashi
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 515 Issue: 4 Pages: 5506-5522
  • DOI: 10.1093/mnras/stac2161
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Isolated Massive Star Formation in G28.20-0.05 (2022)
  • Author(s): Law Chi-Yan、Tan Jonathan C.、Gorai Prasanta、Zhang Yichen、Fedriani Ruben、Tafoya Daniel、Tanaka Kei E. I.、Cosentino Giuliana、Yang Yao-Lun、Mardones Diego、Beltran Maria T.、Garay Guido
  • Journal Title: The Astrophysical Journal Volume: 939 Issue: 2 Pages: 120-120
  • DOI: 10.3847/1538-4357/ac90c7
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The SOFIA Massive (SOMA) Star Formation Survey. IV. Isolated Protostars (2022)
  • Author(s): Fedriani Ruben、Tan Jonathan C.、Telkamp Zoie、Zhang Yichen、Yang Yao-Lun、Liu Mengyao、De Buizer James M.、Law Chi-Yan、Beltran Maria T.、Rosero Viviana、Tanaka Kei E. I.、Cosentino Giuliana、Gorai Prasanta、Farias Juan、Staff Jan E.、Whitney Barbara
  • Journal Title: The Astrophysical Journal Volume: 942 Issue: 1 Pages: 7-7
  • DOI: 10.3847/1538-4357/aca4cf
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] The Power of Outflows in Low-metallicity Star Formation (2023)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: Protostars and Planets VII
  • Int'l Joint Research
• [Presentation] MAgellanic Outflow and chemistry Survey (MAGOS): The Power of Molecular Outflows in Low-metallicity Star Formation (2023)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: The Olympian Symposium 2023
  • Int'l Joint Research
• [Presentation] The Power of Molecular Outflows in Low-metallicity Star Formation (2023)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: ALMA at 10 years: Past, Present, and Future
  • Int'l Joint Research
• [Presentation] The Spicy Genesis of Massive Stars (2023)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: Simulating Physics in Celestial Ecosystems (SPiCE)
  • Int'l Joint Research
• [Presentation] 大小マゼラン雲における原始星アウトフロー観測 (2023)
  • Author(s): 田中圭
  • Organizer: 近傍宇宙の観測的研究で探る星間物質ライフサイクル
  • Invited
• [Presentation] Hot Disks in Massive Star Formation (2023)
  • Author(s): 田中圭
  • Organizer: 惑星形成討論会2023春
• [Presentation] MAGellanic Outflow and chemistry Survey (MAGOS) II: 大小マゼラン雲原始 星アウトフローの物理特性 (2023)
  • Author(s): 田中圭, Yichen Zhang, 下西隆, 富田賢吾, Jonathan C. Tan, 野村英子, John Bally
  • Organizer: 日本天文学会2023年春季年会
• [Presentation] The hot and dynamical birth of massive stars (2023)
  • Author(s): Kei E. I. Tanaka
  • Organizer: 宇宙電波懇談会シンポジウム
  • Invited
• [Presentation] Massive Star Formation: Now & Then (2022)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: A half century of mm/submm astronomy
  • Int'l Joint Research
• [Presentation] Massive Protostellar Disks as a Hot Laboratory (2022)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: DIG (Dust, Ice, and Gas) Astrochemistry
  • Int'l Joint Research / Invited
• [Presentation] Massive Star Formation in Different Environments (2022)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: Star Formation in Different Environments 2022
  • Int'l Joint Research / Invited
• [Presentation] The Hot and Dynamic Birth of Massive Stars (2022)
  • Author(s): Kei E. I. Tanaka
  • Organizer: the 44th COSPAR Scientific Assembly
  • Int'l Joint Research / Invited
• [Presentation] Massive Star Formation at Various Metallicities (2022)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: From Stars to Galaxies II
  • Int'l Joint Research
• [Presentation] Metallicity Dependences of Massive Star Formation from Theoretical and Observational Perspectives (2022)
  • Author(s): Kei E. I. Tanaka et al.
  • Organizer: IAU Symposium 361: Massive Stars Near and Far
  • Int'l Joint Research
• [Presentation] The Hot and Dynamic Birth of Massive Stars from the ngVLA Perspective (2022)
  • Author(s): Kei E. I. Tanaka, Yichen Zhang, Kazuhito Motogi
  • Organizer: Computational Astrophysics in the ngVLA Era
  • Int'l Joint Research