初期の太陽系におけるコンドルールと耐火性インクルージョンの同時形成
Shoichi Itoh1, Hisayoshi Yurimoto
1Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
Nature
|June 13, 2003
まとめ
初期の太陽系物質であるコンドルールとカルシウムとアルミニウムに富んだインクルージョン (CAI) は,重複する形成を示しています. CAIの内部で発見されたコンドルル断片は,太陽の星雲の同時発生と同位体変動を示唆している.
科学分野:
- 惑星科学は惑星科学である.
- 宇宙化学 (コスモケミストリー)
- 初期の太陽系進化について
背景:
- コンドルルとカルシウム・アルミニウム豊富なインクルージョン (CAI) は,熱処理によって形成された原始的な太陽系材料です.
- 以前は,CAIがコンドルールより約200万年前に形成されたと考えられていた.
- 初期の太陽星雲における酸素同位体組成の変動は十分に理解されていない.
研究 の 目的:
- コンドルルとCAI形成の間の時間的,空間的な関係を調査する.
- 新しく発見されたコンドルール-CAI関連の酸素同位体組成を分析するために.
- 初期の太陽星雲の条件への影響を理解するために.
主な方法:
- CAIに埋め込まれたコンドルール断片の顕微鏡検査.
- コンドルルとCAI成分 (メリライト核とマントル) の酸素同位体分析.
- CAIを含むコンドルルと同位体組成に関する既存のデータとの比較.
主要な成果:
- CAI内のコンドルル断片の発見.
- コンドルル断片は16O-poorである.
- CAIは16Oに乏しいメリライト核と16Oに富んだ火性マントルを展示しています.
結論:
- コンドルルとCAIの形成は,時間と空間で重なり合っている可能性が高い.
- 太陽の星雲では酸素同位体組成の大きな変動が発生した.
- これらの波動は,天体物理脈動と同期していたのかもしれない.
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