Abstract:
The halo system of the Milky way comprises the vast majority of the presently observed metal-poor ([Fe/H] <1.0) and very metal-poor ([Fe/H] <2.0) stars. A sizable fraction (~ 30%) of the metal-poor stars with carbon enhancement ([C/Fe] ≤0.7) are called the Carbon-Enhanced Metal-Poor (CEMP) stars. Studies on these objects are of special interest, as they bear the fossil records of nucleosynthesis of the earliest generation of stars. Thus they provide insight into the nucleosynthesis and chemical evolution of the early universe. In the recent past, although these stars have drawn considerable attention as far as their spectroscopic studies are concerned, several questions still remain poorly understood such as the origin, production mechanism(s) and distribution of carbon and neutron-capture elements abundances exhibited by these objects. A comprehensive study of the abundance patterns of various heavy elements in these objects can give important clues to these questions. We have undertaken to perform chemical composition studies of a selected sample of CEMP stars using Hanle Echelle Spectrograph on the 2-m Himalayan Chandra Telescope. In this work, we present abundance results for HE 01100406. Our analysis shows this object to exhibit characteristic properties of CH giants. The abundance distribution patterns and the elemental abundance ratios are critically examined based on existing theories to understand their origin and evolution.
