ANALYSIS OF CARBON-ENHANCED METAL-POOR STARS

Abstract

This proposal is a continuity of the post doctoral project that has been developed by the applicant at the University of Hertfordshire, within the Dr Sean G. Ryan group, which is a detailed analysis of very metal-poor stars that show high overabundance of carbon ([C/Fe] > 1), called CEMP (carbon-enhanced, metal-poor) stars. These stars have been found to show different abundance patterns, and according to the characteristic overabundances they are classified as CEMP-no, CEMP-s, CEMP-r, CEMP-r/s, and CEMP-alpha, depending on the degree to which neutron-capture elements are unenhanced/enhanced according to s-process/r-process/hybrid processes, or are enhanced in alpha-elements. For one sample of stars, the atmospheric parameters will be available at the begining of this project, whereas for another sample, they will be derived during this project. Also, all abundances will be derived through spectrum synthesis at high resolution for as much chemical elements as possible, in order to include representative elements of several nucleossynthetic processes. We intend to contribute to the understanding of the origin of the peculiarities of these stars.