高赤移り銀河の周辺のライマン-α 放射は,ほぼ全空を覆っている
L Wisotzki1, R Bacon2, J Brinchmann3,4
1Leibniz-Institut für Astrophysik Potsdam (AIP), Potsdam, Germany. lwisotzki@aip.de.
Nature
|October 3, 2018
まとめ
研究者はライマン・アルファ放射を用いて 淡い銀河の周りの環銀河媒体をマッピングしました この研究により 宇宙の水素の大半が 検出可能になり 銀河の環境に関する 新たな洞察が得られました
科学分野:
- 天体物理学
- 宇宙学
- 銀河の進化
背景:
- 銀河は,銀河間流入と銀河間流出によって供給される広大なガス貯蔵庫 (環銀河媒介) を宿している.
- この環銀河媒体の空間的分布は 十分に理解されていない.
- ライマン・アルファ放射は 銀河の周りの温かいガスの 重要なトレーサーであり,特に赤偏移が大きい場合です.
研究 の 目的:
- ライマン・アルファ放射を用いて銀河周水素の空間分布を調査する.
- 表面の明るさが低いという課題を克服し,広範囲の放射を検出します.
- サイマン・アルファエミーターの 発生率を測るため
主な方法:
- 浅い表面のライトマン・アルファ放射の観測 淡い銀河を囲む赤偏移3〜6
- トレーサーとして原子水素のライマン・アルファ変換を用いる.
- 予想される空の覆いと 発生率の分析
主要な成果:
- ライトマン・アルファの放射は,弱々しい銀河の周りの100パーセントに近い.
- ライマン・アルファエミテーターの発生率は,ユニットよりかなり高い.
- この速度は,クエーザースペクトルで検出された高柱密度の吸収器と同等である.
結論:
- この研究は,赤偏移3-6のほとんどの環銀河原子水素がライマン・アルファ放射によって検出されたことを示唆している.
- 銀河周りの環境をマッピングするための新しい方法を提供します.
- 発見は,環銀河媒体の放射特性と吸収特性を関連付けています.
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