中子俘获元素增丰恒星中的同位素丰度比研究

CEMP-r/s星的形成机制涉及到了所有的中子俘获核合成过程（包括s-过程、r-过程和i-过程），因而在中子俘获核合成研究领域具有独特的地位。本项目以CEMP-r/s星为主要研究样本，CEMP-s星、r-II星、CH星、Ba星和post-AGB星等中子俘获元素增丰恒星作为比较样本，采用更高层级的同位素丰度分析法，确定上述恒星的Ba、Eu同位素比例，通过比较分析上述样本星的同位素比例，进而更加精确、细致地刻画出各种中子俘获过程在同位素水平上的观测特征及其对金属丰度的依赖关系。通过与AGB星s-过程和i-过程的计算结果进行详细对比，探究i-过程存在的可能性，研究相关恒星的中子俘获核合成历史，确定CEMP-r/s星的形成机制，揭示银河系早期发生各种中子俘获核合成的天体物理环境特征。

CEMP-r/s stars have a unique status in the study field of neutron-capture nucleosynthesis, because whose origin is involved in all of the neutron-capture process (including r-, s- and i-process). In this project, we will make CEMP-r/s stars as the main research samples, the other special objects such as CEMP-s, r-II, CH, Ba stars, post-AGB stars and so on as comparing sample. Through the comparative analysis of Ba and Eu isotope ratios of above samples, we will depict the observed characteristics of every neutron-capture process more accurately and detailedly at the isotopic level, and reveal its dependency on metallicities. By compared with the calculation results of i-process and AGB models with s-process, we will explore the possibility of the existence of i-process, study history of every neutron-capture process, determine the forming mechanism of CEMP-r/s stars, and reveal characteristics of astrophysical environment for every neutron-capture process at the early Milky Way.