恒星形成を推進するリマンα系におけるH Iの解消
Rongmon Bordoloi1, John M O'Meara2, Keren Sharon3
1Department of Physics, North Carolina State University, Raleigh, NC, USA. rbordol@ncsu.edu.
Nature
|May 18, 2022
まとめ
密度の高いガスの貯蔵庫である 湿ったライマン・アルファ系は 23万8千平方キロメートル以上の大きさであることが判明しました これらのシステムには 重要な中性水素が含まれていて 初期の銀河の星形成に 燃料を供給しています
科学分野:
- 宇宙ガスの貯蔵庫
- 初期の宇宙の銀河形成
- 天体物理学スペクトロスコーピー
背景:
- 密度の高い原子ガスは主に水素で,赤偏移3で中性ガスの90%を占める.
- 鈍化したライマン・アルファ系 (DLA) は,背景クエザールとガンマ線爆発で研究された特定の光子を吸収します.
- 過去の研究では,DLAの物理的な範囲に制限はありませんでした.
研究 の 目的:
- 湿ったライマン・アルファシステムの物理的な範囲と特性を決定する.
- これらの初期の宇宙構造の 中性水素含有量と質量を調査する
- その後の恒星形成に 果たす役割を評価する
主な方法:
- 赤道偏移2.7で重力レンズ化された銀河のインテグラルフィールドスペクトロスコーピー.
- 前面の2つのライマンアルファ系を分析した.
- システムの範囲,中性水素柱の密度,総質量の測定
主要な成果:
- 2つのDLAは238,000平方キロメートル以上の範囲で特定されました.
- 中性水素柱の密度は,小さなスケール (<3キロパーセック) で著しく変化した.
- 柱の平均密度は10^20.46から10^20.84cm^-2までで,質量は太陽質量5.5×10^8から1.4×10^9を超えていた.
結論:
- DLAは物理的に大きな構造で,以前に推測されたものよりかなり大きい.
- 恒星形成のための十分な燃料を示しています. 恒星形成のための十分な燃料を示しています.
- この発見は,赤道偏移が大きい大型の低輝度原始銀河の進化における DLA の役割を支持している.
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