Interstellar Carbon in Meteorites
Interstellar Carbon in Meteorites
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陨石中的星际碳
作者：
Peter K. Swart;M. Grady;Colin Pillinger;Roy S. Lewis;E. Anders
默奇森和阿连德玄武岩含有高达百万分之五的碳，其碳13含量高达百万分之1100（碳12与碳13的比例约为42，而陆地碳的比例为88至93）。这种“重”碳与氖-22和反常的氪和氙有关，显示出s过程的特征（慢时间尺度上的中子俘获）。它显然代表了从晚型恒星喷射出来的星际颗粒。第二种异常氙成分（“CCF 3”）与一种独特的轻碳（碳-13的贫化率为每密耳38）有关，然而，它福尔斯地球范围，因此可能是本地或外来的起源。
The Murchison and Allende chondrites contain up to 5 parts per million carbon that is enriched in carbon-13 by up to + 1100 per mil (the ratio of carbon-12 to carbon-13 is approximately 42, compared to 88 to 93 for terrestrial carbon). This "heavy" carbon is associated with neon-22 and with anomalous krypton and xenon showing the signature of the s-process (neutron capture on a slow time scale). It apparently represents interstellar grains ejected from late-type stars. A second anomalous xenon component ("CCFXe") is associated with a distinctive, light carbon (depleted in carbon-13 by 38 per mil), which, however, falls within the terrestrial range and hence may be of either local or exotic origin.