マゲランの冠の観測
Dhanesh Krishnarao1,2,3, Andrew J Fox4, Elena D'Onghia5
1Space Telescope Science Institute, Baltimore, MD, USA. dkrishnarao@coloradocollege.edu.
Nature
|September 28, 2022
まとめ
科学者達は 大マゲラン雲 (LMC) と 小マゲラン雲 (SMC) の周りに 暖かいガス状のハローを発見し マゲランのコロナと名付けました この発見により これらの銀河の進化と 銀河系との相互作用が 理解できるようになります
科学分野:
- 銀河外天文学
- 銀河の進化
- 宇宙ガスの物理
背景:
- 大マゲラン雲 (LMC) と小マゲラン雲 (SMC) は,近隣の衛星銀河である.
- 過去の質量測定では,LMCは熱いガス状のハロー (マゲランのコロナ) を持つべきだと示唆しています.
- ガス構造であるマゲラン流は このハローの影響を受けていると考えられています
研究 の 目的:
- 予言されたマゲランのコロナの証拠を 見つけるためだ
- LMCとSMCを取り巻く環銀河媒質 (CGM) を特徴づけること.
- 銀河のダイナミクスとガス蓄積における マジェランのコロナの役割を理解するために
主な方法:
- 背景クエザーの紫外線 (UV) 吸収スペクトロスコーピーを利用した.
- O+5,C+3,Si+3のような高イオン化種のスペクトルシグネチャーを探した.
- マジェランのCGM内のガスの空間的分布とイオン化状態を分析した.
主要な成果:
- O+5の吸収を検知することでマゲランのコロナを証明した.
- C+3とSi+3の吸収によって コロナを間接的に検出した.
- 多相マゲランCGMの特徴は,少なくとも35 kpcの長さで,合計イオン化された質量は10^9.1Mである.
結論:
- マゲランのコロナの存在が確認され 理論的な予測が裏付けられました
- マジェランのコロナは 多段階のCGMの 構成要素です
- この発見は,マゼランのシステムの性質とその局所グループ内の共同進化を理解するために不可欠です.
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