摘要
基于大量贫金属星元素丰度的观测资料,以太阳系重元素丰度分布为标准,选取Sr、Ba、Eu分别作为贫金属星弱s-过程、主要s-过程、r-过程3种核合成的典型元素,采用参数化方法,分析了不同核合成过程对贫金属星重元素丰度的贡献比例.研究表明:金属丰度越高,弱s-过程、主要s-过程对较轻的中子俘获元素丰度的贡献就越大,较重的中子俘获元素主要由r-过程和主要s-过程产生;金属丰度较低,重中子俘获元素丰度主要由r-过程产生,星系早期弱s-过程对元素丰度几乎没有贡献.
The abundance distribution of heavy elements of solar system is considered as the standard abundance pattern in this paper. Based on a large number of observational data of element abundances in metal-poor stars, St, Ba and Eu are chosen as the repre- sentative elements for the weak s-process, main s-process and r-process, respectively. The parameterized method is adopted to explore the heavy element abundance pattern of these stars. Then the different contributions from three kinds of neutron-capture processes to the abundance distribution of heavy elements are discussed. It is shown that, considering the stars with metallicities similar to the solar system, the contributions from three kinds of neutron-capture processes to this abundance distribution are also similar to the solar system. The heavy elements of the metal-poor stars are mainly produced by r- and main s-neutron-capture processes at low metallicity.
出处
《天文学报》
CSCD
北大核心
2010年第3期221-227,共7页
Acta Astronomica Sinica
基金
国家自然科学基金(10973006)资助项目
关键词
核反应
核合成
恒星
基本参数
星系
丰度
nuclear reactions, nucleosynthesis, stars
fundamental parameters, galaxy abundances
