Star Formation Scenario Suggested by Numerical Simulations

• Project/Area Number: 25400232
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: Kyushu University
• Principal Investigator: Machida Masahiro 九州大学, 理学研究院, 准教授 (10402786)
• Project Period (FY): 2013-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000); Fiscal Year 2016: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2015: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 星形成 / 惑星形成 / 原始惑星系円盤 / 磁気流体力学 / ジェット / 降着円盤 / 大質量星 / アウトフロー / 磁場 / 原始星ジェット / 分子雲コア / 初期宇宙 / 連星 / 星団 / 惑星 / 初代星 / 金属欠乏星 / 星周円盤 / 数値シミュレーション / 磁気流体 / 分子雲

Outline of Final Research Achievements

Stars are the important constitute of the Universe and play a role in the dynamical and chemical evolution of the Universe. Recent ALMA observations are unveiling the vary early phase of the star formation. Using numerical simulations, this study investigates the the star formation process in molecular cloud cores which are parent of stars. In addition, comparing observations with simulation results, the formation process of circumstellar disks and driving mechanism of outflow and jet are clarified. Finally, a new formation scenario of star is constructed.

Research Products

• [Journal Article] Different modes of star formation: gravitational collapse of magnetically subcritical cloud (2018)
  • Author(s): Machida, Masahiro N.; Higuchi, Koki; Okuzumi, Satoshi
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 473 Issue: 3 Pages: 3080-3094
  • DOI: 10.1093/mnras/stx2589
  • Peer Reviewed
• [Journal Article] Massive outflows driven by magnetic effects in star-forming clouds with high mass accretion rates (2018)
  • Author(s): Matsushita, Yuko; Machida, Masahiro N.; Sakurai, Yuya; Hosokawa, Takashi
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 475 Issue: 1 Pages: 1026-1049
  • DOI: 10.1093/mnras/stx893
  • Peer Reviewed
• [Journal Article] Circumstellar disks and outflows in turbulent molecular cloud cores: possible formation mechanism for misaligned systems (2017)
  • Author(s): Tomoaki Matsumoto; Masahiro, N. Machida; Shu-Ichiro Inutsuka
  • Journal Title: The Astrophysical Journal Volume: 839(1) Issue: 1 Pages: 69-69
  • DOI: 10.3847/1538-4357/aa6a1c
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Grand-design Spiral Arms in a Young Forming Circumstellar Disk (2017)
  • Author(s): Kengo Tomida, Masahiro N. Machida, Takashi Hosokawa, Yuya Sakurai, Chia Hui Lin
  • Journal Title: The Astrophysical Journal Letters Volume: 835 Issue: 1 Pages: 11-18
  • DOI: 10.3847/2041-8213/835/1/l11
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Revealing a Detailed Mass Distribution of a High-density Core MC27/L1521F in Taurus with ALMA (2016)
  • Author(s): Tokuda, K., Onishi, T., Matsumoto, T., Saigo, K., Kawamura, A., Fukui, Y., Inutsuka, S.-i., Machida, M. N., Tomida, K., Tachihara, K., and Andre, P.
  • Journal Title: The Astrophysical Journal Volume: 826 Issue: 1 Pages: 26-35
  • DOI: 10.3847/0004-637x/826/1/26
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] ALMA Band 8 Continuum Emission from Orion Source I (2016)
  • Author(s): Hirota, Tomoya; Machida, Masahiro N.; Matsushita, Yuko; Motogi, Kazuhito; Matsumoto, Naoko; Kim, Mi Kyoung; Burns, Ross A.; Honma, Mareki
  • Journal Title: The Astrophysical Journal Volume: 833 Issue: 2 Pages: 238-243
  • DOI: 10.3847/1538-4357/833/2/238
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] The origin of rotation profiles in star-forming clouds (2016)
  • Author(s): Takahashi, Sanemichi Z.; Tomida, Kengo; Machida, Masahiro N.; Inutsuka, Shu-ichiro
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 463 Issue: 2 Pages: 1390-1399
  • DOI: 10.1093/mnras/stw1994
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Conditions for circumstellar disc formation - II. Effects of initial cloud stability and mass accretion rate (2016)
  • Author(s): Machida, Masahiro N.; Matsumoto, Tomoaki; Inutsuka, Shu-ichiro
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 463(4) Issue: 4 Pages: 4246-4267
  • DOI: 10.1093/mnras/stw2256
  • Peer Reviewed
• [Journal Article] Effects of Ohmic and ambipolar diffusion on formation and evolution of first cores, protostars, and circumstellar discs (2015)
  • Author(s): Tsukamoto, Y., Iwasaki, K., Okuzumi, S., Machida, M.~N., Inutsuka, S
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 452 Issue: 1 Pages: 278-288
  • DOI: 10.1093/mnras/stv1290
  • Peer Reviewed / Open Access
• [Journal Article] Bimodality of Circumstellar Disk Evolution Induced by the Hall Current (2015)
  • Author(s): Tsukamoto, Y., Iwasaki, K., Okuzumi, S., Machida, M.~N., Inutsuka, S.
  • Journal Title: The Astrophysical Journal Letters Volume: 810 Issue: 2 Pages: 26-31
  • DOI: 10.1088/2041-8205/810/2/l26
  • Peer Reviewed / Open Access
• [Journal Article] Accretion phase of star formation in clouds with different metallicities (2015)
  • Author(s): Machida, Masahiro N.; Nakamura, Teppei
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 448 Issue: 2 Pages: 1405-1429
  • DOI: 10.1093/mnras/stu2633
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Conditions for circumstellar disc formation: effects of initial cloud configuration and sink treatment (2014)
  • Author(s): Machida, M. N., Inutsuka, S. & Matsumoto, T.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 438 Issue: 3 Pages: 2278-2306
  • DOI: 10.1093/mnras/stt2343
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Formation, orbital and thermal evolution, and survival of planetary-mass clumps in the early phase of circumstellar disc evolution (2013)
  • Author(s): Tsukamoto, Yusuke, Machid a, M. N., Inutsuka, S
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 436 Issue: 2 Pages: 1667-1673
  • DOI: 10.1093/mnras/stt1684
  • Peer Reviewed
• [Journal Article] A SEMI-ANALYTICAL DESCRIPTION FOR THE FORMATION AND GRAVITATIONAL EVOLUTION OF PROTOPLANETARY DISKS (2013)
  • Author(s): Sanemichi Z. Takahashi, Shu-ichiro Inutsuka, and Masahiro N. Machida
  • Journal Title: The Astrophysical Journal Volume: 770 Issue: 1 Pages: 71-80
  • DOI: 10.1088/0004-637x/770/1/71
  • Peer Reviewed
• [Journal Article] The formation of Population III stars in gas accretion stage: effects of magnetic fields (2013)
  • Author(s): Machida, Masahiro N.; Doi, Kentaro
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 435 Issue: 4 Pages: 3283-3305
  • DOI: 10.1093/mnras/stt1524
  • Peer Reviewed
• [Presentation] 大質量星形成における角運動量輸送 (2017)
  • Author(s): 松下祐子, 町田正博, 細川隆史, 櫻井祐也
  • Organizer: 日本天文学会
  • Place of Presentation: 九州大学
  • Year and Date: 2017-03-15
• [Presentation] 低金属量星形成過程で駆動される原始星ジェットの可能性 (2017)
  • Author(s): 樋口公紀, 町田正博, 須佐元
  • Organizer: 日本天文学会
  • Place of Presentation: 九州大学
  • Year and Date: 2017-03-15
• [Presentation] 大質量降着率における原始星からの磁気アウトフローの駆動条件 (2016)
  • Author(s): 松下祐子、町田正博
  • Organizer: 日本天文学会
  • Place of Presentation: 愛媛大学
  • Year and Date: 2016-09-14
• [Presentation] 宇宙の進化と星形成過程の変遷 (2016)
  • Author(s): 樋口公紀, 町田正博, 須佐元
  • Organizer: 日本天文学会
  • Place of Presentation: 愛媛大学
  • Year and Date: 2016-09-14
• [Presentation] Jets and Outflows driving in the low-mass star formation process (2016)
  • Author(s): Masahiro Machida
  • Organizer: STAR FORMATION IN DIFFERENT ENVIRONMENTS
  • Place of Presentation: Quy Nhon, Viet Nam
  • Year and Date: 2016-07-25
  • Int'l Joint Research / Invited
• [Presentation] 磁場と回転の効果による円盤の方向の空間依存性 (2015)
  • Author(s): 町田正博
  • Organizer: 日本天文学会
  • Place of Presentation: 甲南大学
  • Year and Date: 2015-09-10
• [Presentation] 異なる金属量における星形成後期段階の進化 (2014)
  • Author(s): 中村鉄平, 町田正博
  • Organizer: 日本天文学会
  • Place of Presentation: 山形大学
  • Year and Date: 2014-09-13
• [Presentation] 星周円盤形成における質量降着率と磁気制動の関係 (2014)
  • Author(s): 町田正博
  • Organizer: 日本天文学会2014年春季年会
  • Place of Presentation: 国際基督教大学
• [Presentation] 磁気制動と星周円盤の形成を適切に計算するための条件 (2013)
  • Author(s): 町田正博
  • Organizer: 日本天文学会2013年秋季年会
  • Place of Presentation: 東北大学