古い円盤は,惑星系を形成する能力がまだあります
Edwin A Bergin1, L Ilsedore Cleeves, Uma Gorti
1Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, Michigan 48109, USA. ebergin@umich.edu
Nature
|February 1, 2013
まとめ
天文学者はTW Hydrae円盤で二酸化水素を検出し,0.05太陽質量を超えるガス質量を明らかにしました. この発見は,円盤が太陽系にある惑星のような惑星を形成するのに十分な物質を持っていることを示唆しています.
科学分野:
- 惑星科学は惑星科学である.
- 天体物理学 天体物理学
- アストロケミストリー アストロケミストリー
背景:
- 原惑星円盤の質量を推定することは,惑星の形成を理解するために極めて重要です.
- 塵の熱放出と一酸化炭素線を用いた現在の方法では,塵の性質とガスと塵の比率が不明であるため,ガス質量の推定値は不確実になります.
- 以前のTW Hydrae円盤の質量の推定値は,0.0005から0.06の太陽質量まで大きく変化していました.
研究 の 目的:
- 恒星TW Hydraeの周りの原惑星円盤のガス質量を正確に決定するために.
- ディスクガスの質量推定のための信頼性の高いトレーサーとしてデウテリド水素を使用する.
- 円盤の質量が,地球に匹敵する惑星系を形成するのに十分であるかどうかを評価する.
主な方法:
- TW Hydraeディスクにおけるデウテリド水素 (HD) の基本的回転移行の検出.
- 観測データをディスクの性質の詳細なモデリングと組み合わせる.
- 総ガス量に対するHDの感受性と,分子水素を反映したHDの分布を利用する.
主要な成果:
- TW Hydraeディスクからの二酸化水素放射の検出が成功しました.
- 導出された円盤の質量は,0.05太陽質量より大きいと推定されています.
- この質量は,惑星形成のために利用可能なガスのかなりの貯蔵庫を示しています.
結論:
- デウテリド水素は,原惑星円盤のガス質量を決定するための効果的なトレーサーです.
- TW Hydraeディスクは,太陽系のような惑星系を形成するのに十分な質量を持っています.
- この研究は,原惑星円盤の質量推定技術を精錬し,惑星形成の可能性についての洞察を提供します.
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