T. Bensby, S. Feltzing, A. Gould, J. A. Johnson, M. Asplund, D. Adén, J. Meléndez, J. G. Cohen, I. Thompson, S. Lucatello, A. Gal-Yam
We have determined detailed elemental abundances and stellar ages for a
sample of now 38 microlensed dwarf and subgiant stars in the Galactic bulge.
Stars with sub-solar metallicities are all old and have enhanced alpha-element
abundances -- very similar to what is seen for local thick disk stars. The
metal-rich stars on the other hand show a wide variety of stellar ages, ranging
from 3-4 Gyr to 12 Gyr, and an average around 7-8 Gyr. The existence of young
and metal-rich stars are in conflict with recent photometric studies of the
bulge which claim that the bulge only contains old stars.
View original:
http://arxiv.org/abs/1201.2013
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