Study of Diversity of Star and Planet Formation

• 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: 21H00048
• 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: Kagoshima University
• Principal Investigator: 高桑 繁久 鹿児島大学, 理工学域理学系, 教授 (50777555)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2022: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2021: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
• Keywords: 惑星形成 / 原始惑星系円盤 / ALMA望遠鏡 / 星、惑星形成 / 星周円盤 / 連星系 / ALMA

Outline of Research at the Start

本研究は、近年、その存在が明らかになってきた、非常に多様な惑星系がどのように形成されているのかを調べる。若い星の周囲で普遍的に観測される分子ガスと個体微粒子「ダスト」からなる円盤「原始惑星系円盤」は、惑星形成の現場である。本研究では、中心星の質量や年齢、さらには星の存在する領域が異なった円盤のALMA望遠鏡による詳細観測を行う。さらに、これらのデータを解析するための専用のソフトウエアツールの開発も行い、円盤での惑星形成の数値モデルも構築する。このようにして観測、数値計算両面で円盤での惑星形成の多様性を調べていく。

Outline of Annual Research Achievements

惑星がいつどのように形成されるのかは、天文学上の重要な未解決問題の一つである。この問題に取り組むためには、生まれたばかりの原始星からより進化の進んだT Tauri型星というさまざまな年齢、さらには太陽質量程度の星から主系列星に満たないような超低質量星まで、さまざまな星周囲での円盤を詳細に観測する必要がある。また過半数の星が双子の星、連星であることから、連星周囲での円盤でどのように惑星が形成されるのかも観測的に明らかにする必要がある。
本研究は、ALMA望遠鏡を用いた超高解像度観測により、さまざまな若い星周囲での円盤の内部構造、運動の詳細を明らかにした。まずALMA望遠鏡の大型観測プログラムeDiskを用いた、太陽質量程度の原始星周囲の円盤の詳細観測では、原始星誕生後、数万年という早い段階から円盤が形成されていることが明らかになった。これらの原始星の観測結果をT Tauri星周囲の円盤の観測結果と比較すると、原始星円盤においては、Tauri星周囲の円盤で見られるようなリング、ギャップ構造が見られないことがわかった。リング、ギャップ構造は惑星の存在の観測的な証拠と考えられるので、この結果は惑星は星の誕生から数十万年の間に急激に進むことを示唆している。
一方、重力的に束縛されておらず、偶然に近接遭遇した「fly-by」したと考えられるT Tauri の連星 ZZ Tau のALMAデータ解析により、fly-byに伴うふたつの星の相対運動を検出した。さらに二つの星は互いに傾いた円盤を持っており、fly-byにより円盤同士が相互作用していることが明らかになった。
また、主系列星になるために必要な質量0.08 太陽質量に満たない超低質量星J162656 の観測では、このような天体においても円盤、すなわち惑星形成の母体が存在していることが示された。

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] 台湾中央研究院/国立清華大学(その他の国・地域)
• [Int'l Joint Research] National Radio Astronomy Observatory/University of Virginia/University of Illinois(米国)
• [Int'l Joint Research] KASI/Seoul National University(韓国)
• [Int'l Joint Research] University of Copenhagen(デンマーク)
• [Int'l Joint Research] 台湾中央研究院(その他の国・地域)
• [Int'l Joint Research] National Radio Astronomy Observatory/University of Virginia/University of Illinois(米国)
• [Int'l Joint Research] KASI/Seoul National University(韓国)
• [Int'l Joint Research] University of Copenhagen(デンマーク)
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). XIV. Flared Dust Distribution and Viscous Accretion Heating of the Disk around R CrA IRS 7B-a (2024)
  • Author(s): Takakuwa Shigehisa、Saigo Kazuya、Kido Miyu、(中略)、Mori Shoji et al.
  • Journal Title: The Astrophysical Journal Volume: 964 Issue: 1 Pages: 24-24
  • DOI: 10.3847/1538-4357/ad1f57
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Formation of Unipolar Outflow and Protostellar Rocket Effect in Magnetized Turbulent Molecular Cloud Cores (2024)
  • Author(s): Takaishi Daisuke、Tsukamoto Yusuke、Kido Miyu、Takakuwa Shigehisa、Misugi Yoshiaki、Kudoh Yuki、Suto Yasushi
  • Journal Title: The Astrophysical Journal Volume: 963 Issue: 1 Pages: 20-20
  • DOI: 10.3847/1538-4357/ad187a
  • Peer Reviewed / Open Access
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). XII. Accretion Streamers, Protoplanetary Disk, and Outflow in the Class I Source Oph IRS 63 (2023)
  • Author(s): Flores Christian、Ohashi Nagayoshi、Tobin John J.、J?rgensen Jes K.、Takakuwa Shigehisa、Li Zhi-Yun、Lin Zhe-Yu Daniel、van ’t Hoff Merel L. R.、Plunkett Adele L.、Yamato Yoshihide、et al.
  • Journal Title: The Astrophysical Journal Volume: 958 Issue: 1 Pages: 98-98
  • DOI: 10.3847/1538-4357/acf7c1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). VIII. A Small Protostellar Disk around the Extremely Low Mass and Young Class 0 Protostar IRAS 15398?3359 (2023)
  • Author(s): Thieme Travis J.、Lai Shih-Ping、Ohashi Nagayoshi、Tobin John J.、J?rgensen Jes K.、(Insa Choi) Jinshi Sai、Aso Yusuke、Williams Jonathan P.、Yamato Yoshihide、et al.
  • Journal Title: The Astrophysical Journal Volume: 958 Issue: 1 Pages: 60-60
  • DOI: 10.3847/1538-4357/ad003a
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). X. Compact Disks, Extended Infall, and a Fossil Outburst in the Class I Oph IRS43 Binary (2023)
  • Author(s): Narayanan Suchitra、Williams Jonathan P.、Tobin John J.、Jorgensen Jes K.、Ohashi Nagayoshi, (Takakuwa Shigehisa), et al.
  • Journal Title: The Astrophysical Journal Volume: 958 Issue: 1 Pages: 20-20
  • DOI: 10.3847/1538-4357/acfd24
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). VI. Kinematic Structures around the Very-low-mass Protostar IRAS 16253-2429 (2023)
  • Author(s): Aso Yusuke、Kwon Woojin、Ohashi Nagayoshi、Jorgensen Jes K.、Tobin John J.、(Takakuwa Shigehisa) et al.
  • Journal Title: The Astrophysical Journal Volume: 954 Issue: 1 Pages: 101-101
  • DOI: 10.3847/1538-4357/ace624
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). IX. High-resolution ALMA Observations of the Class 0 Protostar R CrA IRS5N and Its Surroundings (2023)
  • Author(s): Sharma Rajeeb、Jorgensen Jes K.、Gavino Sacha、Ohashi Nagayoshi、Tobin John J.、(Takakuwa Shigehisa) et al.
  • Journal Title: The Astrophysical Journal Volume: 954 Issue: 1 Pages: 69-69
  • DOI: 10.3847/1538-4357/ace35c
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). V. Possible Annular Substructure in a Circumstellar Disk in the Ced110 IRS4 System (2023)
  • Author(s): Sai Insa Choi Jinshi、Yen Hsi-Wei、Ohashi Nagayoshi、(中略)、Mori Shoji et al.
  • Journal Title: The Astrophysical Journal Volume: 954 Issue: 1 Pages: 67-67
  • DOI: 10.3847/1538-4357/ace52d
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). VII. Keplerian Disk, Disk Substructure, and Accretion Streamers in the Class 0 Protostar IRAS 16544?1604 in CB 68 (2023)
  • Author(s): Kido Miyu et al.
  • Journal Title: The Astrophysical Journal Volume: 953 Issue: 2 Pages: 190-190
  • DOI: 10.3847/1538-4357/acdd7a
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Chemical Differentiation around Five Massive Protostars Revealed by ALMA: Carbon-chain Species and Oxygen/Nitrogen-bearing Complex Organic Molecules (2023)
  • Author(s): Taniguchi Kotomi、Majumdar Liton、Caselli Paola、Takakuwa Shigehisa、Hsieh Tien-Hao、Saito Masao、Li Zhi-Yun、Dobashi Kazuhito、Shimoikura Tomomi、Nakamura Fumitaka、Tan Jonathan C.、Herbst Eric
  • Journal Title: The Astrophysical Journal Supplement Series Volume: 267 Issue: 1 Pages: 4-4
  • DOI: 10.3847/1538-4365/acd110
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS (2023)
  • Author(s): Yamato Yoshihide et al.
  • Journal Title: The Astrophysical Journal Volume: 951 Issue: 1 Pages: 11-11
  • DOI: 10.3847/1538-4357/accd71
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). III. A First High-resolution View of Submillimeter Continuum and Molecular Line Emission toward the Class 0 Protostar L1527 IRS (2023)
  • Author(s): van ’t Hoff Merel L. R.、Tobin John J.、Li Zhi-Yun、Ohashi Nagayoshi、Jorgensen Jes K.、 (Takakuwa Shigehisa), et al.
  • Journal Title: The Astrophysical Journal Volume: 951 Issue: 1 Pages: 10-10
  • DOI: 10.3847/1538-4357/accf87
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). II. Limited Dust Settling and Prominent Snow Surfaces in the Edge-on Class I Disk IRAS 04302+2247 (2023)
  • Author(s): Lin Zhe-Yu Daniel、Li Zhi-Yun、Tobin John J.、Ohashi Nagayoshi、... Yamato Yoshihide、et al.
  • Journal Title: The Astrophysical Journal Volume: 951 Issue: 1 Pages: 9-9
  • DOI: 10.3847/1538-4357/acd5c9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Early Planet Formation in Embedded Disks (eDisk). I. Overview of the Program and First Results (2023)
  • Author(s): Ohashi Nagayoshi et al.
  • Journal Title: The Astrophysical Journal Volume: 951 Issue: 1 Pages: 8-8
  • DOI: 10.3847/1538-4357/acd384
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Galaxy clusters at z~1 imaged by ALMA with the Sunyaev-Zel'dovich effect (2023)
  • Author(s): T. Kitayama, S. Ueda, N. Okabe, T. Akahori, M. Hilton, J. P. Hughes, Y. Ichinohe, K. Kohno, E. Komatsu, Y.-T. Lin, H. Miyatake, M. Oguri, C. Sifon, S. Takakuwa, M. Takizawa, T. Tsutsumi, J. van Marrewijk, E. J. Wollack
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 75 Issue: 2 Pages: 311-337
  • DOI: 10.1093/pasj/psac110
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211 (2023)
  • Author(s): Yen Hsi-Wei、Koch Patrick M.、Lee Chin-Fei、Hirano Naomi、Ohashi Nagayoshi、(Insa Choi) Jinshi Sai、Takakuwa Shigehisa、Tang Ya-Wen、Tatematsu Ken’ichi、Zhao Bo
  • Journal Title: The Astrophysical Journal Volume: 942 Issue: 1 Pages: 32-32
  • DOI: 10.3847/1538-4357/aca47f
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A VLA View of the Flared, Asymmetric Disk around the Class 0 Protostar L1527 IRS (2022)
  • Author(s): Sheehan Patrick D.、Tobin John J.、Li Zhi-Yun、Aikawa, Y.（24名中18番目）他
  • Journal Title: The Astrophysical Journal Volume: 934 Issue: 2 Pages: 95-95
  • DOI: 10.3847/1538-4357/ac7a3b
  • Peer Reviewed / Open Access / Int'l Joint Research
• [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] Carbon-chain Chemistry versus Complex-organic-molecule Chemistry in Envelopes around Three Low-mass Young Stellar Objects in the Perseus Region (2021)
  • Author(s): Taniguchi Kotomi、Majumdar Liton、Takakuwa Shigehisa、Saito Masao、Lis Dariusz C.、Goldsmith Paul F.、Herbst Eric
  • Journal Title: The Astrophysical Journal Volume: 910 Issue: 2 Pages: 141-141
  • DOI: 10.3847/1538-4357/abe854
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Misaligned Twin Molecular Outflows from the Class 0 Protostellar Binary System VLA 1623A Unveiled by ALMA (2021)
  • Author(s): Hara Chihomi、Kawabe Ryohei、Nakamura Fumitaka、Hirano Naomi、Takakuwa Shigehisa、Shimajiri Yoshito、Kamazaki Takeshi、Di Francesco James、Machida Masahiro N.、Tamura Motohide、Saigo Kazuya、Matsumoto Tomoaki、Tomida Kengo
  • Journal Title: The Astrophysical Journal Volume: 912 Issue: 1 Pages: 34-34
  • DOI: 10.3847/1538-4357/abb810
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Misaligned Circumstellar Disks and Orbital Motion of the Young Binary XZ Tau (2021)
  • Author(s): Ichikawa Takanori、Kido Miyu、Takaishi Daisuke、Shimajiri Yoshito、Tsukamoto Yusuke、Takakuwa Shigehisa
  • Journal Title: The Astrophysical Journal Volume: 919 Issue: 1 Pages: 55-55
  • DOI: 10.3847/1538-4357/ac0dc3
  • Peer Reviewed / Open Access
• [Journal Article] Chemical Compositions in the Vicinity of Protostars in Ophiuchus (2021)
  • Author(s): Taniguchi Kotomi、Majumdar Liton、Plunkett Adele、Takakuwa Shigehisa、Lis Dariusz C.、Goldsmith Paul F.、Nakamura Fumitaka、Saito Masao、Herbst Eric
  • Journal Title: The Astrophysical Journal Volume: 922 Issue: 2 Pages: 152-152
  • DOI: 10.3847/1538-4357/ac214e
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] ALMAよるClass II 連星 XZ Tau の互いに傾いた星周円盤と軌道運動の検出 (2022)
  • Author(s): 高桑 繁久
  • Organizer: 連星系・変光星研究会2022 in 鹿児島大学
• [Presentation] Current Status of the ALMA Large Program eDisk (2022)
  • Author(s): 高桑 繁久
  • Organizer: 新学術領域「新しい星形成理論によるパラダイムシフト」大研究会
• [Presentation] ALMAよるClass II 連星 XZ Tau の互いに傾いた星周円盤と軌道運動の検出 (2022)
  • Author(s): 高桑 繁久
  • Organizer: 連星系・変光星研究会2022 in 鹿児島大学
• [Presentation] Current Status of the ALMA Large Program eDisk (2022)
  • Author(s): 高桑 繁久
  • Organizer: 新学術領域「新しい星形成理論によるパラダイムシフト」大研究会
• [Presentation] 星と惑星形成の多様性を繋ぐ基礎研究 (2021)
  • Author(s): 高桑 繁久
  • Organizer: 新学術領域「星惑星形成」後半戦キックオフミーティング