若い恒星の周りの破片ディスクには,分子水素の豊富な貯蔵庫がある
W F Thi1, G A Blake, E F van Dishoeck
1Leiden Observatory, PO Box 9513, 2300 Leiden, The Netherlands.
Nature
|May 9, 2001
まとめ
分子水素 (H2) の観測は,恒星の破片円盤に相当するガスを明らかにし,一酸化炭素に基づく以前の発見に異議を唱える. この発見は,破片円盤がこれまで考えられていたよりも多くのガスを保持し,惑星形成理論に影響を与える可能性があることを示唆しています.
科学分野:
- 天文学と天体物理学について
- 惑星科学は惑星科学である.
背景:
- 星周積分円盤は,星や惑星の形成に不可欠です.
- メインシーケンスの恒星の周りの破片円盤は,炭素一酸化物 (CO) の観測に基づいて,ガス/塵比 < 0.1.1 のガスが少ないと考えられていた.
研究 の 目的:
- 分子水素 (H2) 観測を用いて,破片ディスクのガス含有量を調査する.
- 破片ディスクのガス/塵の比率を再評価し,星間値と比較する.
主な方法:
- 分子水素 (H2) の最も低い回転移行を観測した.
- ベータ・ピクトリス,49セティ,HD135344.4の周辺の破片ディスクからのデータを分析した.
主要な成果:
- 瓦の円盤に大量のガスが検出されました.
- 計算されたガス質量は,COベースの推定値より数百〜千倍大きい.
- 星間値 (~100) と比較可能なガス/塵の比率を決定した.
結論:
- 破片ディスクには,以前の仮定に反して,かなりの量のガスが含まれている可能性があります.
- 瓦円盤に豊富なガスの存在は,進行中の惑星形成と円盤の進化に影響を及ぼします.
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