G. Israelian, S. BertrŠn de Lis, E. Delgado Mena, V. Zh. Adibekyan
It is well known that at a given [Fe/H] below solar metallicities the thick disk stars are more enhanced in their alpha -element abundances than the thin disk. We report prelminary results for abundances of Cu, Ba and Y in a sample of 762 stars observed with the HARPS spectrograph. Precise and homogeneous abundance analysis reveals interesting trends related to Galactic Chemical Evolution. Significant differences between the thick and thin disk populations are found for [Cu/Fe], [Y/Fe] and [Ba/Fe]. When comparing the abundance distributions in thick and thin disks, we found that Ba and Y are underabundant, while Cu is overabundant in thick disk stars at all metallicities. We found smooth and distinct abundance trends that for the thin and thick disks are clearly separated.
Memorie della Societa Astronomica Italiana
SAIt, Number 85, Page 265