Metal rich stars in omega Cen: preliminary FLAMES GTO results
arXiv:astro-ph/0410695 · doi:10.1007/978-3-540-34136-9_39
Abstract
I present preliminary results for a sample of ~700 red giants in omega Cen, observed during the Ital-FLAMES Consortium GTO time in May 2003, for the Bologna Project on omega Cen. Preliminary Fe and Ca abundances confirm previous results: while the metal-poor and intermediate populations show a normal halo alpha-enhancement of [alpha/Fe]=$+0.3, the most metal-rich stars show a significantly lower [alpha/Fe]=+0.1. If the metal-rich stars have evolved within the cluster in a process of self-enrichment, the only way to lower their alpha-enhancement would be SNe type Ia intervention.
2 pages, 1 figure. Contributed talk to "Chemical Abundances and Mixing in Stars in the Milky Way and its Satellites", help in Castiglione della Pescaia in September 2004