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Updated: Jul 19, 2026

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Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
太陽雲の異質性は,pプロセスのサマリウムとネオジミウム同位体における異質性である
Rasmus Andreasen1, Mukul Sharma
1Radiogenic Isotope Geochemistry Laboratory, Department of Earth Sciences, Dartmouth College, 6105 Sherman Fairchild Hall, Hanover, NH 03755, USA.
まとめ
炭酸性コンドライトは,サマリウム-144 (144Sm) の欠乏を示し,初期の太陽雲の中で異質な分布を示しています. これは,pプロセスの元素とrプロセスの元素の異なる超新星源を示唆しています.
科学分野:
- 宇宙化学 (コスモケミストリー)
- 核天体物理学 核天体物理学とは
- 惑星科学 惑星科学
背景:
- 大量炭酸コンドライトは,144Sm (約144Sm) の有意な欠乏を示しています. 100ppm) と比較すると,他の隕石や地上の基準に比べて,
- この赤字は,142Nd/144Nd比率が約142Nd/144Ndの減少と相関しています. これらの隕石には1ppmの11ppmがある.
研究 の 目的:
- 炭酸性コンドライト内のサマリウム (Sm) とネオジミウム (Nd) の同位体異常を調査する.
- 初期の太陽星雲の異なる核合成プロセスから発生した Sm と Nd の同位体の分布パターンを決定する.
主な方法:
- 大量炭酸コンドライトにおけるサマリウムとネオジミウムの同位体分析.
- 同位体比を地上のおよび他の隕石の基準と比較.
- 核合成起源 (pプロセス,rプロセス,sプロセス) に基づく同位体異質性のモデリング.
主要な成果:
- 144Smの有意な赤字と142Nd/144Ndの相応の減少は,炭酸性コンドライトで確認されました.
- 超新星におけるpプロセスによって生成された同位体は,太陽の星雲の中で異質的に分布していた.
- rプロセス (超新星) とsプロセス (赤い巨人) で生成された同位体は均質に分布していることが判明しました.
結論:
- pプロセスの Sm と Nd の同位体の異質な分布は,これらの核素の異なるまたは弱い接続の超新星源を暗示する.
- rプロセスの同位体とsプロセスの同位体の均質な分布は,これらの元素をそれぞれの源からより均質に混合することを示唆しています.
- この同位体証拠は,初期の太陽星雲の元素組成に責任を負う天体物理的な場所と混合プロセスを制限する.
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