A holistic abundance analysis of r-rich stars
A holistic abundance analysis of r-rich stars
复制标题
富含r恒星的整体丰度分析
DOI：
10.1111/j.1365-2966.2010.17374.x
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发表时间：
2010-10
影响因子：
4.8
通讯作者：
BO ZHANG
中科院分区：
文献类型：
--
作者：
JIANG ZHANG;WENYUAN CUI;BO ZHANG
贫金属恒星的化学丰度是一个很好的测试平台，它可以为低金属丰度下的中子捕获过程模型设定新的约束条件。一些富r过程（以下简称富r）的贫金属恒星，如HD 221170，表现出较重的中子俘获元素的过剩和较轻的中子俘获元素的过剩。对这些富r恒星的研究可以使我们更好地了解低金属丰度下的弱和主r过程核合成。基于对贫金属恒星观测的结论和中子俘获元素核合成理论，我们建立了一个模型来确定弱r过程和主r过程对贫金属恒星重元素丰度的相对贡献。利用该模型，我们发现大多数样品恒星的轻元素丰度模式接近弱r过程恒星的模式，而较重的中子俘获元素的丰度模式与主r过程恒星的模式非常相似，而较轻的中子俘获元素可以通过弱r过程和主r过程物质的混合来拟合。弱r过程元素的产生似乎与轻元素有关，而主要r过程元素的产生几乎与轻元素的产生脱钩。我们将我们的结果与低金属丰度的观测数据进行了比较，结果表明，至少在金属丰度[Fe/H] < -2.1范围内，我们的预测趋势与观测趋势非常吻合。对于大多数样本恒星来说，中子捕获元素和轻元素的丰度模式可以用在分子云中形成的恒星来最好地解释，该分子云中已经被弱和主r过程物质污染了。
The chemical abundances of metal-poor stars are an excellent test bed by which to set new constraints on models of neutron-capture processes at low metallicity. Some r-process-rich (hereafter r-rich) metal-poor stars, such as HD 221170, show an overabundance of the heavier neutron-capture elements and excesses of lighter neutron-capture elements. The study of these r-rich stars could give us a better understanding of weak and main r-process nucleosynthesis at low metallicity. Based on conclusions from the observation of metal-poor stars and neutron-capture element nucleosynthesis theory, we set up a model to determine the relative contributions from weak and main r-processes to the heavy-element abundances in metal-poor stars. Using this model, we find that the abundance patterns of light elements for most sample stars are close to the pattern of weak r-process stars, and those of heavier neutron-capture elements very similar to the pattern of main r-process stars, while the lighter neutron-capture elements can be fitted by the mixing of weak and main r-process material. The production of weak r-process elements appears to be associated with the light elements, while the production of main r-process elements is almost decoupled from that of the light elements. We compare our results with the observed data at low metallicities, showing that the predicted trends are in good agreement with the observed trends, at least for the metallicity range [Fe/H] < -2.1. For most sample stars, the abundance patterns of both neutron-capture elements and light elements could be best explained by a star formed in a molecular cloud that has been polluted by both weak and main r-process material.
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DOI：
10.1086/300289
发表时间：
1998-04
期刊：
The Astronomical Journal
影响因子：
--
作者：
A. McWilliam
通讯作者：
A. McWilliam
影响因子：
6.5
作者：
Wolfgang Hayek;Wolfgang Hayek;U. Wiesendahl;N. Christlieb;Kjell Eriksson;A. Korn;P. Barklem;
通讯作者：
Wolfgang Hayek;Wolfgang Hayek;U. Wiesendahl;N. Christlieb;Kjell Eriksson;A. Korn;P. Barklem;
DOI：
10.1086/504069
发表时间：
2006-04
期刊：
The Astrophysical Journal
影响因子：
--
作者：
I. Ivans;J. Simmerer;C. Sneden;J. Lawler;J. Cowan;R. Gallino;S. Bisterzo
通讯作者：
I. Ivans;J. Simmerer;C. Sneden;J. Lawler;J. Cowan;R. Gallino;S. Bisterzo
DOI：
10.1086/503195
发表时间：
2006-02
期刊：
The Astrophysical Journal
影响因子：
--
作者：
S. Honda;W. Aoki;Y. Ishimaru;S. Wanajo;S. Ryan
通讯作者：
S. Honda;W. Aoki;Y. Ishimaru;S. Wanajo;S. Ryan
DOI：
10.1086/307512
发表时间：
1998-08
期刊：
The Astrophysical Journal
影响因子：
--
作者：
J. Cowan;B. Pfeiffer;K. Kratz;F. Thielemann;C. Sneden;S. Burles;D. Tytler;T. Beers
通讯作者：
J. Cowan;B. Pfeiffer;K. Kratz;F. Thielemann;C. Sneden;S. Burles;D. Tytler;T. Beers