赤い偏移20で原子水素で最初の星のサイン
Eli Visbal1, Rennan Barkana, Anastasia Fialkov
1Jefferson Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138, USA. evisbal@fas.harvard.edu
Nature
|June 23, 2012
まとめ
初期の宇宙の星形成は,異なる物質速度によって抑制された. シミュレーションでは,最初の星から21cmの強化された水素信号が発せられ,これはラジオ望遠鏡で検出できる.
科学分野:
- 宇宙学と天体物理学について
- 初期の宇宙に関する研究.
- 最初の恒星形成が始まりました.
背景:
- 初期の宇宙では,暗黒物質とバリオン物質は異なる速度で移動し,特定の地域では星形成を抑制しました.
- 初期の恒星からの21cmの水素信号 (赤偏移20) の以前の推定では,X線ガスの加熱と抑制の強化のような重要な要因が無視されました.
- 速度の違いにより,最初の星はより巨大なハローで形成される (約. 100万太陽質量) は,これまで考えられていたよりも大きい.
研究 の 目的:
- 赤道偏移20で最初の星の分布をシミュレートする.
- 異なる物質速度の影響,X線ガス加熱,そして星形成に対する抑制の強化を組み込むために.
- これらの初期の星の観測可能な21cmの水素シグネチャーを予測するために.
主な方法:
- 初期の宇宙の大規模な宇宙学的シミュレーション (400メガパーセックボックス) を実行しました.
- ダークマターとバリオン物質の速度差,X線加熱,星形成抑制の物理学が含まれていた.
- 最初の星の分布とその21cmの水素信号を分析した.
主要な成果:
- 最初の星からの21cmの水素シグネチャーは,100メガパーセックのスケールで強化された変動信号 (10ミリケルビン) です.
- 信号は,顕著なバリオン音響振動を持つ平らな電力スペクトルを示しています.
- 観測感度は,マーチソン広場配列や低周波配列 (50~100MHz) などの機器で,千時間の統合時間内に達成可能である.
結論:
- ダークマターとバリオン物質の異なる速度は,初期の恒星形成と21cmの信号に大きな影響を与えます.
- シミュレートされた21cmの水素信号は,最初の星の時代への新しい観測可能な窓を提供します.
- 将来のラジオ望遠鏡観測は,この予測された信号を検出し,宇宙の夜明けの洞察を提供することができます.
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