環恒星炭酸の"乾燥した"凝縮源である
Alice Toppani1, François Robert, Guy Libourel
1Centre de Recherches Pétrographiques et Géochimiques-CNRS UPR 2300, 15 rue Notre Dame des Pauvres, BP 20, Vandoeuvre-les-Nancy, France. toppani2@llnl.gov
Nature
|October 21, 2005
まとめ
以前は水と結びついていた炭酸塩鉱物は,宇宙でシリケートとアビオジェニックで形成される. この発見は,高温で密度の高い恒星環境における宇宙炭酸塩の新たな起源を示唆している.
科学分野:
- アストロケミストリー アストロケミストリー
- 惑星科学は惑星科学である.
- ミネラロジーは,鉱物学です.
背景:
- 炭酸塩鉱物は,プロトスターのような天体物理環境で検出されます.
- アビオジェニック炭酸は,通常,CO2豊富な水による水性変化を示します.
- 惑星性星雲や原星における最近の検出は,この指標の妥当性を疑問視しています.
研究 の 目的:
- 天体物理カルボネートの代替形成経路を調査する.
- 炭酸塩の形成における非均衡濃縮の役割を調査する.
- 液体の水がない環境における炭酸塩の起源を理解する.
主な方法:
- 非均衡凝縮の実験シミュレーション.
- シリケートガスがH2O-CO2豊富な蒸気の中で凝縮される.
- 同濃縮の無形シリケートおよび炭酸塩の分析.
主要な成果:
- 炭酸塩のアビオジェニック形成が,無形シリケートと共に示されている.
- 不均衡の過程で成功した共濃縮が発生した.
- 液体の水なしで炭酸塩の形成を好む条件を特定しました.
結論:
- 天体物理カルボネートは,宇宙における非均衡凝縮によって形成される可能性があります.
- 提案された形成部位には,進化した恒星風や原星外流が含まれる.
- これは,観測された宇宙炭酸塩の代替説明を提供する.
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