宇宙で最初の星が誕生した
Tom Abel1, Greg L Bryan, Michael L Norman
1Harvard Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA.
まとめ
シミュレーションでは,銀河前ハロ1つにつき,巨大な金属のない星が1つしか形成されないことが示されています. これは,ガスが冷却され,崩壊し,密度の高い核を形成し,急激に単一のプロトスターに収縮し,さらなる恒星形成を制限するときに起こります.
科学分野:
- コスモロジー・コスモロジーとは
- 天体物理学 天体物理学
- 計算科学 計算科学とは
背景:
- 構造形成モデルは,最初は暗黒物質が優勢で,密度の乱れから形成された銀河前の物体があることを示しています.
- 原始的なガスは水素分子を介して冷却され,暗黒物質の潜在的な井戸に沈み,分子雲の類似体を形成します.
研究 の 目的:
- 自己一貫した3D水力学モデルを使用して,宇宙の最初の星の一つの形成をシミュレートします.
- 初期の宇宙構造における断片化と恒星形成の過程を調査する.
主な方法:
- 完全に自己一貫した3次元水力学シミュレーションが採用されました.
- シミュレーションは,冷却と分子形成を含む,暗黒物質のハロの中で原始的なガスの崩壊を追跡しました.
主要な成果:
- 約100太陽質量の密度の高い核が形成され,急速な収縮を経験した.
- 予想とは対照的に,核は断片化しなかった;代わりに,単一の1太陽質量プロトスターは,三体H2形成によって形成された.
- 急速な増殖 (10−2太陽質量/年) と原星からの放射的フィードバックが観察されました.
結論:
- 銀河前ハロ1つにつき,大質量で金属のない恒星が最大1つしか形成されない.
- 形成中の星からの放射的フィードバックは,同じハロー内のさらなる星形成を阻害する.
- この結果は,銀河のハロで金属が少ない星の数量測定と一致しています.
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