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Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
膨らみのない矮星銀河と,超新星による流出によるダークマターのコア
F Governato1, C Brook, L Mayer
1Astronomy Department, University of Washington, Seattle, Washington 98195, USA.
Nature
|January 16, 2010
まとめ
新しいシミュレーションでは,超新星による流出が,矮星銀河形成における冷暗物質 (CDM) の問題を解決できることを示しています. これは,CDM理論と観測された矮星銀河の性質の間の不一致を解決する.
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
- 銀河の形成 銀河の形成
背景:
- 標準的な冷暗物質 (CDM) モデルは,矮星銀河の観測された性質を説明するのに苦労しています.
- 矮星銀河は,通常,回転する恒星円盤,巨大なダークマターのハロ,恒定密度のコアを呈しており,CDMの予測とは対照的に,密度の高い膨らみや中央の急なダークマターのプロフィールがある.
- 現存するモデルでは,理論的な予測と現在の矮星銀河の観測データとの調和が取れず,CDMモデルにとって大きな課題となっている.
研究 の 目的:
- 水力力学シミュレーションで不均質な恒星間介質を解決することで,矮星銀河の性質をCDMモデルと調和させることができるかどうかを調査する.
- シミュレーション内の特定の物理的プロセスが,矮星銀河の観測された特性を自然に生成できるかどうかを判断する.
主な方法:
- CDMと宇宙定数を含むフレームワーク内で水力力学シミュレーションを実施しました.
- ガスダイナミクスを正確にモデル化するために,不均質な恒星間媒体を解明することに焦点を当てています.
- シミュレート銀河におけるガスと暗黒物質の分布に対する超新星による流出の影響を分析した.
主要な成果:
- シミュレーションにより,超新星からの強い流出が,低角度モメントのガスを効果的に除去することが示されています.
- このプロセスは,密度の高い恒星突起の形成を阻害する.
- 重要なことに,これらの流出は,中央キロパーセックスの内の中央暗黒物質の密度を半分以上減少させます.
結論:
- シミュレーションは,自然に,ボリュームのない,浅い中央ダークマターのプロフィールを持つ矮星銀河の類型を生成します.
- これは,CDMモデルに対して,矮星銀河が抱える長年の課題を解決する.
- この発見は,CDMモデルが,複雑なバリオン物理学が正確に組み込まれるとき,矮星系を含む銀河の形成を説明するのに有効であることを示唆しています.
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