Solar nebula heterogeneity in p-process samarium and neodymium isotopes
Solar nebula heterogeneity in p-process samarium and neodymium isotopes
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DOI：
10.1126/science.1131708
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发表时间：
2006-11-03
期刊：
影响因子：
56.9
通讯作者：
Sharma, Mukul
中科院分区：
文献类型：
--
作者：
Andreasen, Rasmus;Sharma, Mukul
相对于其他陨石和地球标准，块状碳质陨石的Sm-144含量约为百万分之100，导致Nd-142/Nd-144比值降低约11 ppm。这些数据表明，在超新星的光致蜕变反应中，由p过程产生的钐和钕同位素在太阳星云中的分布是不均匀的。超新星中的快中子俘获（r过程）和红巨星中的慢中子俘获（s过程）产生的其他钐和钕同位素分布均匀。因此，为太阳星云提供p-和r-过程核素的超新星源是断开的，或者只是弱连接的。
Bulk carbonaceous chondrites display a deficit of similar to 100 parts per million (ppm) in Sm-144 with respect to other meteorites and terrestrial standards, leading to a decrease in their Nd-142/Nd-144 ratios by similar to 11 ppm. The data require that samarium and neodymium isotopes produced by the p process associated with photodisintegration reactions in supernovae were heterogeneously distributed in the solar nebula. Other samarium and neodymium isotopes produced by rapid neutron capture (r process) in supernovae and by slow neutron capture (s process) in red giants were homogeneously distributed. The supernovae sources supplying the p- and r-process nuclides to the solar nebula were thus disconnected or only weakly connected.