前惑星円盤における大きな塵粒の放射線圧力混合
1Physics Department, University of Split, Nikole Tesle 12, 21000 Split, Croatia. vinkovic@pmfst.hr
Nature
|May 16, 2009
まとめ
若い恒星の塵状円盤には,大きな結晶粒子が含まれています. 赤外線は,より大きな粒子を内部の円盤から引き上げ,冷たい地域へ輸送し,再入りを可能にします.
科学分野:
- 天文学 天文学
- 天体物理学 天体物理学
- 惑星科学は惑星科学である.
背景:
- 若い恒星の物体は,無形で微小粒子の粒からなる塵の蓄積円盤を持っています.
- 観測により,彗星,隕石,若い星のスペクトルに大きな結晶粒子が発見され,これは高温処理 (>1,000 K) であったことを示している.
- 熱い内部の円盤から冷たい外部の領域にこれらの加工穀物を輸送するための既存のモデルは,潜在的な問題を持つ複雑な混合機構を伴う.
研究 の 目的:
- 原惑星円盤内で加工された穀物を運ぶための新しいメカニズムを調査する.
- 粉塵のディスクの冷たい領域に大きな結晶粒子が存在することを説明するために.
主な方法:
- 粉塵に包まれたディスクからの赤外線放射線圧力に基づく理論的モデリングを用いた.
- 赤外線放射線圧力によるより大きな塵粒 (>1マイクロメートル) のロフティングと外への輸送をシミュレートする.
- 放射線圧力のサポートが不十分であるため,冷たい円盤領域に穀物の再侵入を分析する.
主要な成果:
- 塵の多い円盤からの赤外線は,内側の円盤からより大きな粒子を (> 1 マイクロメートル) 浮揚させることができます.
- 恒星放射線の圧力は,これらの浮揚した粒子を円盤の上から外へ推進します.
- 粒子は,温度が低く,放射線圧が持続的なサポートに不十分であるより大きな半径でディスクに戻ります.
結論:
- 赤外線放射線圧力を含む新しいメカニズムにより,冷たい円盤領域に加工された穀物の存在が説明されています.
- この過程は,粒子のロフト化と外向きの輸送を伴うもので,ほとんどの若い恒星物体や若い茶色矮星では一般的かもしれない.
- この発見は,熱的に変化した塵粒子の唯一の輸送メカニズムである大規模な混合に関する以前の仮定に異議を唱える.
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