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

Abstract

HE 1005-1439 is a carbon-enhanced metal-poor (CEMP) star with [Fe/H]$\sim -3.0$, which is largely enhanced in elements produced by slow neutron-capture process (s-process; e.g., [Ba/Fe]=1.16$\pm 0.31$, [Pb/Fe]=$1.98\pm 0.19$), and mildly enhanced in elements produced by rapid neutron-capture process (r-process; e.g., [Eu/Fe]=0.46$\pm 0.22$). 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. Using the combination of s-process and r-process abundances, we fully fit the abundance patterns of the neutron-capture elements of this star. We find that the neutron-capture elements are mainly produced by the s-process of the AGB companion with low mass and low metallicity, and the r-process nucleosynthesis also contributes a little to this star.