SMSS J031300.36-670839.3 星の金属の源として,単一の低エネルギー,鉄の少ない超新星である
S C Keller1, M S Bessell1, A Frebel2
1Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Cotter Road, Weston, Australian Capital Territory 2611, Australia.
Nature
|February 11, 2014
まとめ
初期の恒星は,低エネルギー超新星によって濃縮されたガスから形成されました. 1つの星,SMSS J031300.36-670839.3は,鉄がなく,単一の低エネルギー超新星イベントが元素の種を蒔いたことを示しています.
科学分野:
- 天文学と天体物理学について
- 恒星の進化について
- 宇宙化学 (コスモケミストリー)
背景:
- 初期の宇宙の構成は,恒星形成と銀河の進化を理解するために重要である.
- 以前のモデルでは,最初の恒星が巨大で,ペア不安定性超新星によって鉄の濃縮につながると示唆されていた.
- 初期の超新星からの鉄の産出量とその後の恒星形成への影響は不明のままである.
研究 の 目的:
- 極めて金属が乏しい星の元素の豊富さを分析することによって,最初の超新星の性質を調査する.
- 初期の恒星が単一の超新星または複数の超新星イベントによって豊かにされたかどうかを決定する.
- 最初の超新星,特にそのエネルギー出力と鉄出力の特性を制限するために.
主な方法:
- 4つの低質量,非常に金属が少ない恒星における元素の豊富度比の分析.
- 恒星SMSS J031300.36-670839.3.3の詳細な光学スペクトル分析が行われました.
- 観測された豊富なパターンと理論的な超新星生産量モデルを比較する.
主要な成果:
- 4つの低質量恒星は,最低でも数回,おそらく1回,低エネルギー超新星からの濃縮の証拠を示しています.
- SMSS J031300.36-670839.3は検出可能な鉄を示さないが,その上限は太陽の10~7.1倍である.
- この恒星の豊富なパターンは, ~60太陽質量の恒星から発生した単一の超新星からの濃縮と一致し,ブラックホールを残しています.
結論:
- 低エネルギー超新星は,初期の宇宙では一般的だった可能性が高い.
- これらの超新星は,軽い元素でガスを豊かにしたが,鉄への貢献はほとんどなかった.
- 低エネルギー超新星からの星のフィードバックの減少は,第一世代の恒星形成の延長を促進し,宇宙再イオン化と銀河の化学的進化に役割を果たした可能性があります.
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