恒星形成の過程における複数の長さスケールの自己重力の役割
Alyssa A Goodman1, Erik W Rosolowsky, Michelle A Borkin
1Initiative in Innovative Computing at Harvard, Cambridge, Massachusetts 02138, USA. agoodman@cfa.harvard.edu
Nature
|January 6, 2009
まとめ
自己重力は,分子雲の中で星が形成されるのに極めて重要です. L1448雲の分析は,自己重力が様々なスケール,特に星前核の星形成に大きく影響することを示しています.
科学分野:
- 天体物理学 天体物理学
- スター・フォーメーション
- コンピューティング天体物理学
背景:
- 自己重力は,恒星形成の遅い段階において,恒星と円盤のシステムに密集した核の崩壊を促し,決定的であることが知られている.
- 分子雲の初期の段階およびより大きなスケール (例えば, ~1パーセック) の自己重力の役割は不明である.
- いくつかのシミュレーションでは,渦巻の断片化だけで,自己重力を考慮せずに恒星の初期質量関数を確立できると示唆しています.
研究 の 目的:
- 恒星形成過程中の分子雲における様々なスケールの自己重力の役割を調査する.
- デンドログラム分析を使用してL1448分子雲を分析し,自己引力構造を特定します.
- 観測結果と,自己重力を含むか除外するシミュレーションを比較する.
主な方法:
- (13) CO.によって追跡されたL1448分子雲の観測データに関するデンドログラム (階層樹図) 分析を使用した.
- コンパクトなプレステラーコアを特定するために,塵の放射ピークを分析しました.
- 観察結果を,自己重力のないシミュレーションのデンドログラム分析と比較した.
主要な成果:
- 自己重力は,L1448分子雲の観測スケールにおいて重要な役割を果たしますが,均一ではありません.
- 星前核の90%以上は,デンドログラム分析によって特定された自己引力構造の中に位置しています.
- 自己重力のないシミュレーションは,観察されたいくつかのスペクトルを模倣しながら,観測されたものよりも自己重力的に見えるガスの割合がはるかに大きいことを示しています.
結論:
- 自己引力コクノンは,恒星前核や恒星形成前の恒星の存在に不可欠な条件であるようです.
- "非自己引力"シミュレーションにおける重力の重要な役割は,それらの仮定と出力の潜在的な矛盾を示しています.
- 自己重力を含めることは,星形成をサブパーセックスケールでリアルにシミュレーションするために不可欠です.
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