Formation of the Abundance Boundaries of the Heavier Neutron-capture Elements in Metal-poor Stars
Formation of the Abundance Boundaries of the Heavier Neutron-capture Elements in Metal-poor Stars
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贫金属恒星中重中子俘获元素丰度边界的形成
DOI：
10.1088/1538-3873/aa6569
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发表时间：
2017
影响因子：
3.5
通讯作者：
Bo Zhang
中科院分区：
文献类型：
--
作者：
Guochao Yang;Hongjie Li;Nian Liu;Lu Zhang;Wenyuan Cui;Yanchun Liang;Ping Niu;Bo Zhang
贫金属恒星中较重的 r 过程元素 (Z>=56) 相对于 Fe ([r/Fe]) 的丰度分散保留了恒星形成历史的极好信息，并为银河系化学富集的各种情况提供了重要的见解。在这方面，[r/Fe]的上下边界可以为研究恒星形成历史和早期银河系化学演化的极端情况提供有用的线索。在本文中，我们研究了气体云的 [r/Fe] 上下边界的形成。我们发现，对于形成贫金属恒星的云，[r/Fe]上限的形成主要是由于单个主要r过程事件的污染。对于形成贫金属恒星的云来说，[r/Fe]下限的形成主要是由于单个 SN II 事件喷射初级 Fe 的污染。
The abundance scatter of heavier r-process elements (Z>=56) relative to Fe ([r/Fe]) in metal-poor stars preserves excellent information of the star formation history and provides important insights into the various situations of the Galactic chemical enrichment. In this respect, the upper and lower boundaries of [r/Fe] could present useful clues for investigating the extreme situations of the star formation history and the early Galactic chemical evolution. In this paper, we investigate the formation of the upper and lower boundaries of [r/Fe] for the gas clouds. We find that, for a cloud from which metal-poor stars formed, the formation of the upper limits of [r/Fe] is mainly due to the pollution from a single main r-process event. For a cloud from which metal-poor stars formed, the formation of the lower limits of [r/Fe] is mainly due to the pollution from a single SN II event that ejects primary Fe.