初期の巨大なホットハローの冷流は,銀河形成の主なモードとして
1Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel. dekel@phys.huji.ac.il
Nature
|January 23, 2009
まとめ
初期の宇宙の巨大な銀河は,合併によってのみ形成されたのではない. 新しい研究によると,それらは冷たいガスの流れから成長し,球形構造が支配する構造ではなく,拡張された回転円盤を形成した.
科学分野:
- コスモロジー・コスモロジーとは
- 銀河の形成と進化について
背景:
- 初期の宇宙の巨大な銀河は,激しい恒星形成を示した.
- 合併の出来事は,この恒星形成の主要な原動力であると推定されています.
- 観測された銀河の性質は,ガスに富み,塊状で,拡張された回転円盤のようなもので,合併による形成モデルにはしばしば矛盾していた.
研究 の 目的:
- 若き宇宙における巨大な銀河のガス蓄積メカニズムを調査する.
- 初期の巨大な銀河の観測された性質を理論的な形成経路と調和させる.
- 銀河形成の合併型モデルに対する代替案を探求する.
主な方法:
- 銀河の形成をモデル化するために宇宙学的シミュレーションを利用した.
- ガス獲得を理解するためにクラスタリング理論を応用した.
- シミュレーション結果を,恒星形成銀河の観測データと比較した.
主要な成果:
- 暗黒物質のハローを貫通する冷たいガスの流れによって形成された"流れで満たされた銀河"を特定しました.
- 最も蓄積されたガスが星に急速に変化することを発見した.
- 円滑な流れは銀河の4分の3を特定の速度で星を形成し,稀なサブミリメートルの銀河の激しい星爆発は合併によって引き起こされることを決定しました.
結論:
- 合併だけでなく,冷たいガス流は,初期の宇宙における巨大な銀河の形成の重要な原動力である.
- 流の蓄積は,回転する円盤構造を保ち,球形状に塊状で乱暴な進化を可能にします.
- このストリーム駆動シナリオは,初期の銀河組立のための合併パラダイムに有効な代替案を提供します.
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