恒星間炭素予算と,炭素が塵や大分子における役割
1Center for Astrophysics and Space Astronomy, University of Colorado, Boulder 80309, USA.
まとめ
太陽は他の恒星よりもはるかに多くの炭素を含んでおり,銀河の組成と超新星核合成の理解に影響を与えています. この発見は既存のモデルに異議を唱え,星間塵の形成に利用できる炭素が少ないことを示唆している.
科学分野:
- 天文学と天体物理学について
- 星の構成 星の構成
- 宇宙化学 (コスモケミストリー)
背景:
- 公開された恒星組成データは,他の銀河の恒星と比較して,太陽の炭素濃度が高いことを示しています.
- 代表的な銀河の星は,約10^6の水素原子に約225の炭素原子を示し,太陽は350から470の値を示している.
研究 の 目的:
- 天体物理モデルに太陽の過剰な炭素の影響を分析する.
- 標準を再評価する.
主な方法:
- 公開された恒星組成データの分析.
- 銀河系と恒星間の平均値と太陽の炭素濃度の比較.
- 核合成と塵形成モデルへの影響の評価.
主要な成果:
- 太陽の炭素の豊富さは,銀河の平均 (225 per 10^6 H) よりも (350-470 per 10^6 H) 大幅に高い.
- 太陽系の他の元素の量が増えたことは,超新星事件と関連していることを示唆している.
- 銀河の炭素予算は限られているため,星間塵のモデルが不合理になる可能性がある.
結論:
- 太陽の炭素含有量が高いため,超新星核合成モデルを改訂する必要がある.
- "宇宙"の組成基準は,太陽系の豊富さのために変更する必要があります.
- 銀河の炭素の減少は,現在の恒星間塵形成理論に課題を投げかけている.
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