宇宙学的距離にある低質量暗黒衛星銀河の重力検出
S Vegetti1, D J Lagattuta, J P McKean
1Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. svegetti@space.mit.edu
Nature
|January 20, 2012
まとめ
天文学者は,重力レンズレンズを用いて,銀河系にある射手座の銀河の質量に似た暗黒の衛星銀河を発見した. この発見は,階層的な銀河形成の冷たい暗黒物質シミュレーションと一致しています.
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
- 銀河の形成 銀河の形成
背景:
- 観測された矮星衛星銀河の数と冷たい暗黒物質 (CDM) のシミュレーションの間に不一致がある.
- 局所グループは,いくつかの観測が予測されたより高い基底構造質量分数を示唆しているため,異常である可能性があります.
- 以前の研究は,質量が非常に低い矮星銀河を検出できないことによって制限されていました.
研究 の 目的:
- 局所宇宙を超えた銀河の基礎構造の質量関数を調査する.
- 銀河形成に関するCDMシミュレーションの予測をテストする.
- 暗黒衛星銀河の質量分数と分布を制限するために.
主な方法:
- アインシュタイン環系 JVAS B1938+666.6.の内部にある暗黒の衛星銀河を検出するために重力レンズを用いた.
- この新発見の銀河のデータを,以前に特定された巨大なダーク・サテライトと組み合わせた.
- 両システムのデータを用いて,サブストラクチャの質量関数を分析した.
主要な成果:
- 赤道偏移0.881.8で (1.9 ± 0.1) × 10 ^ 8の太陽質量を持つ暗黒の衛星銀河の発見を報告した.
- 基底構造質量関数の対数傾きを1.1 (((+0.6) (((-0.4) として決定しました.
- 基底構造の平均質量分数は3.3 (((+3.6) (((-1.8%) であった.
結論:
- 観測されたサブストラクチャの質量関数と質量分子は,95%の信頼レベルでのCDMシミュレーションと一致しています.
- この発見は,CDM宇宙内の階層的な銀河形成モデルを支持する.
- この研究は,より高い赤偏移の暗黒衛星銀河の存在と分布の重要な証拠を提供します.
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