コスモロジカルな距離にある銀河から21センチメートルの水素放射
M A Zwaan1, P G van Dokkum, M A Verheijen
1School of Physics, University of Melbourne, Victoria 3010, Australia. mzwaan@physics.unimelb.edu.au
まとめ
研究者らは,赤道偏移z = 0.18.18でアベル2218星団内の銀河で中性原子水素 (HI) を検出しました. これは,銀河団内の効率的なガス除去メカニズムを示唆し,銀河の増殖率に影響を与える.
科学分野:
- 天文学と天体物理学について
- コスモロジー・コスモロジーとは
- 銀河の進化 銀河の進化 銀河の進化
背景:
- 銀河団は,銀河の進化を研究するための重要な環境です.
- 中性原子水素 (HI) は,恒星形成の重要な燃料であり,銀河のガス含有量のトレーサーである.
- 星団のガス除去メカニズムを理解することは,銀河の運命を理解するために不可欠です.
研究 の 目的:
- 銀河団アベル2218.8における中性原子水素 (HI) 放射を検出する.
- 豊かなクラスター環境内の銀河のガス含量と増殖速度を調査する.
- クラスターアセンブリに関する宇宙学的モデルをテストする.
主な方法:
- ウェスターボーク・シンセシス・ラジオ望遠鏡 (WSRT) を利用して,機敏な無線観測を行った.
- 標的は銀河団アベル2218で,赤道偏移はz = 0.18であった.
- 中性原子水素 (HI) の21cmの放射線を特定するために分析されたスペクトルデータ.
主要な成果:
- Abell 2218星団の中心から2.0h65(-1) Mpcに位置するスパイラル銀河からの中性原子水素 (HI) 放射を成功裏に検出しました.
- クラスター内で他の重要なHI検出は行われず,効率的なガス剥離を示しています.
- 過去10億年にわたって,ガスに富んだ銀河が3つ未満の低い増殖率を推論した.
結論:
- アベル2218の中性ガスの効率的な除去は,クラスター環境が銀河のガス含有量に大きく影響することを示唆しています.
- 推論された低収縮率は,銀河団がより高い赤偏移 (z > 1) で集合する低密度宇宙学的モデルをサポートしています.
- この研究は,密度の高い宇宙構造の中で銀河の進化モデルに対する観測的制約を提供します.
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