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銀河中心のブラックホールの周りの冷たい蓄積円盤
Elena M Murchikova1,2, E Sterl Phinney3, Anna Pancoast4
1Institute for Advanced Study, Princeton, NJ, USA. lena@ias.edu.
Nature
|June 7, 2019
まとめ
天文学者は,銀河系の中央にある超大質量ブラックホールである Sagittarius A* の近くで,イオン化されたガスの回転円盤を検出しました. この発見は,H30αスペクトルラインを用いて,以前は観測によって制限されていなかったガスの性質を明らかにした.
科学分野:
- 天体物理学と天文学
- ブラックホールの研究
- 銀河の中心におけるガスダイナミクス
背景:
- 銀河系の中央にある超大質量ブラックホールである Sagittarius A*の質量は太陽質量4×106です.
- 熱いガスと冷たいガスの貯蔵庫が Sagittarius A*を囲んでいますが,ブラックホールの蓄積地帯にある冷たいガスの質量は制限されていません.
- 水素再結合スペクトルラインは,この冷たいガスを検出するための潜在的な方法を提供します.
研究 の 目的:
- 射手座A*を囲む 冷たいイオン化されたガスの円盤の画像と特徴を
- このガスコンポーネントの質量と密度を制限する.
- 超大質量ブラックホールの すぐ近くにあるガスを制御する 物理的過程を調査する
主な方法:
- H30α水素再結合線を観測するために1.3ミリメートルのラジオ天文学を用いた.
- 射手座A*の2×10^4シュワルツシルト半径以内のガスの円盤をイメージした.
- 二重ピークの放射線プロフィールと空間分布を分析し,ガス特性を推測した.
主要な成果:
- 射手座A*の周りを回る 10^4ケルビンのイオン化されたガスの円盤を成功裏に撮影した.
- 円盤は,全速度線幅約2,200 km/sの二重ピークのH30α放射線を示している.
- 観測された放射は予想より強く,H30α移行のマザー強化を示唆しています.
結論:
- 観測は,太陽の質量10^5から10^4の推定質量と,水素密度10^5から10^6cm^3の回転するガスの円盤を明らかにした.
- 赤色シフトと青色シフトの配列の空間的移動は円盤内の回転を示している.
- 強化されたH30α放射はマザー増幅を示唆し,ブラックホールの近くのガスの物理を理解するための重要な発見です.
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