s- and r-process elements in two very metal-poor stars
Abstract
New measurements of neutron-capture elements are presented for two very metal-poor stars ([Fe/H] ~ -3). One (LP 625-44) has an s-process signature believed to be due to mass transfer from a now-extinct metal-poor AGB companion, and the second (CS 22897-008) is one of a number of very metal-poor stars having high [Sr/Ba] ratios which is not expected from the r-process. In the s-process star, many elements including lead have been detected, providing strong constraints on the 13C pocket in the now-extinct AGB star. In the Sr-rich star, Zn, Y, and Zr are also seen to be overabundant, and several possible nucleosynthesis mechanisms are discussed.
Cite
@article{arxiv.astro-ph/0008423,
title = {s- and r-process elements in two very metal-poor stars},
author = {Sean G. Ryan and Wako Aoki and Lisa A. J. Blake and John E. Norris and Timothy C. Beers and Roberto Gallino and Maurizio Busso and Hiroyasu Ando},
journal= {arXiv preprint arXiv:astro-ph/0008423},
year = {2007}
}
Comments
10 pages, 3 figures. Proc. Torino-Melbourne-Pasadena "Wasserburg" Workshop, U. Torino, 21-22 June 2000. For publication in Mem.S.A.It