近赤外線背景アニソトロピーは,銀河の拡散したイントラハロ光によるものです
Asantha Cooray1, Joseph Smidt, Francesco De Bernardis
1Department of Physics and Astronomy, University of California, Irvine, California 92697, USA. acooray@uci.edu
Nature
|October 27, 2012
まとめ
宇宙近赤外線背景アニソトロピーは,初期の銀河や矮星銀河から発生している可能性があります. 新しい測定は,より大きなクラスタリング振幅を明らかにし,銀河内のイントラハロ星が赤道シフト1〜4の主要な寄与者であることを示唆しています.
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:
- 宇宙の近赤外線背景放射 (CNIRB) の解明されていないアニゾトロピーは,初期の銀河 (再イオン化の時代) と弱く,矮星銀河と関連しています.
- 以前の研究では,CNIRBアニソトロピーの主要な源を決定的に決定するために十分な空間スケールの解像度がありませんでした.
- これらの情報源を区別することは,初期の宇宙の銀河集団と進化を理解するために極めて重要です.
研究 の 目的:
- CNIRBのアニソトロピーパワースペクトルを,幅広い角度スケール (亜弧分から1度) で測定する.
- 既存のモデルと新しい測定を比較することによって,CNIRBアニソトロピーの支配的な起源を調査する.
- 現在のモデルが観測結果と一致しない場合,イントラハロライトなどの代替説明を探求する.
主な方法:
- 宇宙近赤外線背景放射のアニソトロピーパワースペクトルの分析.
- サバークミニュートから1度までの角度尺度で測定します.
- 観測されたパワースペクトルの比較と,初期の銀河や矮星銀河のモデルからの予測.
主要な成果:
- CNIRBのアニソトロピーのクラスタリング振幅の測定は,初期の銀河や矮星銀河のみに基づいたモデルによって予測されるよりも高い.
- ショットノイズのレベルは,淡い銀河からの貢献と一致しており,新しい観測されていないソース集団の必要性を排除しています.
- 観測を説明するために,クラスタリング振幅を高める物理的メカニズムが必要です.
結論:
- 観測されたCNIRBのアニソトロピーは,銀河内のイントラハロ星によって説明され,初期の銀河や矮星によってのみ説明されない.
- 0.07%から0.2%のイントラハロ光の分子は,赤偏移1〜4.4で暗黒物質ハロ (109〜1012太陽質量) の観測と一致しています.
- この発見は,宇宙赤外線背景と銀河の進化に対するイントラハロ光の重要な貢献を強調しています.
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