2018 Fiscal Year Final Research Report
Exploring mass distribution of first stars and their impact on galaxy formation by a large spectroscopic survey of early generation stars
| Project/Area Number |
16H02168
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | National Astronomical Observatory of Japan |
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Principal Investigator |
Aoki Wako 国立天文台, TMT推進室, 准教授 (20321581)
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| Co-Investigator(Kenkyū-buntansha) |
藤本 正行 北海学園大学, 工学部, 客員研究員 (00111708)
冨永 望 甲南大学, 理工学部, 教授 (00550279)
野本 憲一 東京大学, カブリ数物連携宇宙研究機構, 上級科学研究員 (90110676)
小笹 隆司 北海道大学, 理学研究院, 特任教授 (90263368)
須田 拓馬 東京大学, 大学院理学系研究科(理学部), 特任助教 (90374735)
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| Research Collaborator |
ISHIGAKI Miho
NOZAWA Takaya
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 金属欠乏星 / 超新星 / 化学進化 / ダスト / 銀河系 |
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| Outline of Final Research Achievements |
To explore the nature of first generation stars and early chemical evolution, which are key to understanding the structure formation and evolution of matter in the universe, we conducted a large spectroscopic survey of metal-poor stars with LAMOST in China and the Subaru Telescope, along with construction of a database of stellar chemical abundances as well as theoretical studies of supernovae, stellar evolution and dust formation. The results of these studies indicate that (1) a majority of first stars should have been massive stars having typical mass of around 13-40 solar masses, (2) low-mass stars are few, if any, among first stars, and (3) dust is formed in the environment of very low-metallicity and affects the star formation process. We also obtained a strong evidence for accretion of a small stellar system like dwarf galaxies into the Milky Way after it experienced chemical evolution.
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| Free Research Field |
天文学
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| Academic Significance and Societal Importance of the Research Achievements |
私たちを形づくる物質、そして地球を含むあらゆる天体が宇宙のなかでどのように作り出されてきたのか--これは人類共通の疑問と言っても過言ではない。宇宙の初期に誕生し、現在でも太陽系の近くに生き残っている星を調べることにより、宇宙の最初に生まれた星は超新星爆発を起こす大質量星であったこと、星や超新星が作り出した多様な元素やダストが後の世代の星形成につながっていったことを様々な角度から調べ、明らかにした。
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