CEMP星HE1005-1439中子俘获元素天体物理来源的研究  

The Astrophysical Origins of Neutron-captue Elements in CEMP Star HE 1005-1439

作　　者：韩万强 杨国超 牛萍 张波[3] HAN Wan-qiang;YANG Guo-chao;NIU Ping;ZHANG Bo(Science College,Shijiazhuang University,Shijiazhuang 050035;School of Physics and Astronomy,China West Normal University,Nanchong 637002;College of Physics,Hebei Normal University,Shijiazhuang 050024)

机构地区：[1]石家庄学院理学院,石家庄050035 [2]西华师范大学物理与天文学院,南充637002 [3]河北师范大学物理学院,石家庄050024

出　　处：《天文学报》2023年第5期50-56,共7页Acta Astronomica Sinica

基　　金：河北省自然科学基金项目(A2018106014、A2019208194);河北省高等学校科学研究项目(ZC2022090);石家庄学院博士科研基金项目(21BS014)资助。

摘　　要：HE1005-1439是一颗金属丰度极低([Fe/H]~=3.0)的碳增丰贫金属星(Carbon Enhanced Metal-Poor,CEMP),该星的s-过程元素显著超丰([Ba/Fe]=1.16±0.31,[Pb/Fe]=1.98±0.19),而r-过程元素温和超丰([Eu/Fe]=0.46±0.22),使用单一的s-过程模型和i-过程模型均不能拟合该星中子俘获丰度分布.采用丰度分解的方法探究该星化学元素的天体物理来源可有助于理解CEMP星的形成和化学演化.利用s-过程和r-过程的混合模型对其中子俘获元素的丰度分布进行拟合,发现该星的中子俘获元素主要来源于低质量低金属丰度AGB伴星的s-过程核合成,而r-过程核合成也有贡献.HE 1005-1439 is a Carbon Enhanced Metal-Poor(CEMP)star with[Fe/H]~-3.0,which is significantly enhanced in elements produced by slow neutron-capture process(s-process;e.g.,[Ba/Fe]=1.16±0.31,[Pb/Fe]=1.98±0.19)and mildly enhanced in elements produced by rapid neutron-capture process(r-process;e.g.,[Eu/Fe]=0.46±0.22).The neutron-capture element patterns of the star can not be fitted by the s-process model or intermediate process(i-process)model.Studying the astrophysical origins of chemical elements in the star based on the method of abundance decomposition can help understanding the formation and evolution of the CEMP stars.Fitting the abundance patterns of the neutron-capture elements in this star with the combination of s-and r-process patterns,we found that the neutron-capture elements of the star are mainly produced by the s-process of the companion AGB stars with low mass and low metallicity,and the r-process nucleosynthesis also contributes a little to this star.

关 键 词：恒星:丰度 恒星:形成 恒星:化学组成特殊 

分 类 号：P144[天文地球—天体物理]