Abundance Analysis of r+s Stars: r-Process Abundance Comparison between r+s Stars and r-rich Stars
Abundance Analysis of r+s Stars: r-Process Abundance Comparison between r+s Stars and r-rich Stars
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DOI：
10.1086/665526
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发表时间：
2012-03
影响因子：
3.5
通讯作者：
Shuai Liang;Hong-jie Li;Xiaojing Shen;W. Cui;Bo Zhang
中科院分区：
文献类型：
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作者：
Shuai Liang;Hong-jie Li;Xiaojing Shen;W. Cui;Bo Zhang
R+S星的化学丰度可以为我们设定S核合成和r核合成模型的约束提供很好的信息。本文用参数模型对32r+S或S富星的元素丰度进行了拟合。我们发现，与r+S星有关的r过程丰度模式与富r星的模式相似。另一方面，r+S恒星的轻元素和铁族元素丰度模式与弱r-过程恒星的模式非常接近。R+S星和富r星最初是在受到弱r过程物质污染的分子云中形成的。与r+S星有关的r过程产额与它们的金属丰度成正比。虽然S过程的起源和位置与r过程有很大的不同，但在r+S星中，S过程和r过程的增强程度之间存在着很强的相关性。这意味着从r过程起源处吸积而来的r过程物质，如AIC或SN1.5，随着从AGB星中吸积的S过程物质的增加而有增加的趋势。
The chemical abundances of the r + s stars can give us excellent information for setting constraints on models of s- and r-process nucleosynthesis. In this article, we fit the element abundances of 32 r + s or s-rich stars by using a parametric model. We find that the r-process abundance pattern related to r + s stars is similar to the pattern of r-rich stars. On the other hand, the abundance pattern of light elements and iron group elements for the r + s stars is very close to the pattern for weak r-process stars. The r + s stars and r-rich stars are initially formed in the molecular cloud, which had been polluted by weak r-process material. The yields of r-process related to r + s stars are proportional to their metallicity. Although the origin and site of the s-process are quite different from those of the r-process, there is a strong correlation between the enhancement level of the s-process and r-process in r + s stars. This implies that r-process matter accreted from the origin of the r-process, such as AIC or SN 1.5, has an increasing trend with increasing s-process matter accreted from the AGB stars.