活発な銀河核からの熱い泡は,冷却フロークラスターの熱源として使用されます.
Marcus Brüggen1, Christian R Kaiser
1International University Bremen, Campus Ring 1, 28759 Bremen, Germany. m.brueggen@iu-bremen.de
Nature
|July 19, 2002
まとめ
銀河団の活発な銀河核は浮気バブルを膨らませる. これらのバブルは,熱いガスを混ぜ,冷却時間を増加させ,以前の冷却フローモデルとは異なり,冷却ガスの堆積を減少させます.
科学分野:
- 天体物理学 天体物理学
- コスモロジー・コスモロジーとは
- プラズマ物理学 プラズマ物理学
背景:
- 銀河団には,熱い,X線を放射するプラズマが含まれています.
- 観測された中央X線明るさのピークは,ガス冷却の流れを示唆しています.
- 予測された冷たいガスと観測された冷たいガスの間には不一致があるため,質量堆積率が低いことが示唆される.
研究 の 目的:
- 銀河団のガス冷却に対する活性銀河核 (AGN) の影響を調査する.
- AGNの活動に照らして冷却フローモデルを再評価する.
- 浮気バブルがガス熱力学に及ぼす影響を定量化する.
主な方法:
- 高解像度の水力力学シミュレーション.
- AGNで膨らんだプラズマバブルをモデリングする.
- シミュレートされたクラスターコアのガスエントロピーと冷却時間を分析する.
主要な成果:
- 浮気バブルがクラスターの大気中に浮き上がり,ガスを動かす.
- シミュレーションでは,内部クラスター領域の冷却時間が増加していることが示されています.
- バブル活動により,冷たいガスの堆積が著しく減少した.
結論:
- AGNが駆動する浮気バブルは,銀河団のガス冷却を調節する上で重要な役割を果たします.
- AGNのフィードバックを考慮しない限り,冷却フローモデルは不完全である可能性があります.
- これらの発見は,観測された冷却ガス量における不一致を調和させるものである.
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