Tracing the origin of neutron-capture elements in the metalpoor star HE 1244-3036

Abstract

We present results from a detailed abundance analysis of a star HE 1244-3036, based on a high resolution (R ∼ 50000) SUBARU/HDS spectrum. The wavelength coverage is from 3510 to 5310 Å. Our estimated metallicity [Fe/H] ∼ −2.5 and carbon abundance ([C/Fe] = 1.06) show that the object belongs to the group of carbon-enhanced metal-poor (CEMP) stars. The location of the star in the Hertzsprung-Russell diagram indicates that the evolutionary phase of the object is the first giant branch. The observed enhancement of the heavy elements is, therefore likely extrinsic in nature. In order to understand the origin of the enhanced abundances of the heavy elements, we have performed a detailed comparison of the observed abundances with theoretical s-process model predictions which shows that the observed abundances can be explained with mass transfer from a companion AGB star with metallicity, z = 0.00005, and mass M = 2M⊙.