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初期の恒星形成の低質量残骸である
R Schneider1, A Ferrara, R Salvaterra
1Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy.
Nature
|April 25, 2003
まとめ
初期の恒星は金属なしで形成され,大質量恒星に好意を示した. しかし,金属度が極めて低いガス中の塵は,今日の質量が低い星の形成を可能にした.
科学分野:
- 天文学 (astronomy) 天文学 (astronomy) とは,天文学 (astronomy) とは,天文学 (astronomy) とは,天文学 (astronomy) とは
- コスモロジー・コスモロジーとは
- 天体物理学 天体物理学
背景:
- ビッグバンの後に形成された最初の星は,その後の恒星世代に大きな影響を与えた.
- 以前の研究によると,巨大な恒星 (太陽の質量100個まで) は金属のない条件で形成され,低質量恒星には金属の濃縮が必要であった.
研究 の 目的:
- 初期の宇宙における低質量星の形成における塵の役割を調査する.
- 観測可能な低質量恒星の形成に必要な最小の金属性を理解するために.
主な方法:
- 既知の恒星の中で最も鉄が少ない恒星の分析.
- 極低金属度ガスの粉塵の存在と影響を調査する.
主要な成果:
- 最も鉄が少ない星は,非常に低い金属度でも塵の存在を示しています.
- この塵は,ガスの冷却に不可欠であり,分子雲の断片化を可能にします.
- 断片化は,質量が低い第2世代恒星の形成につながります.
結論:
- 金属だけでなく,塵も,初期の恒星形成において重要な役割を果たしています.
- 塵の存在は,低質量星の形成を促進し,それらは今日まで生き残ることができます.
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