T. Bensby, A. Alves-Brito, M. S. Oey, D. Yong, J. Meléndez
Based on high-resolution spectra obtained with the MIKE spectrograph on the
Magellan telescopes we present detailed elemental abundances for 64 red giant
stars in the inner and outer Galactic disk. For the inner disk sample (4-7 kpc
from the Galactic centre) we find that stars with both thin and thick disk
abundance patterns are present while for Galactocentric distances beyond 10
kpc, we only find chemical patterns associated with the local thin disk, even
for stars far above the Galactic plane. Our results show that the relative
densities of the thick and thin disks are dramatically different from the solar
neighbourhood, and we therefore suggest that the radial scale length of the
thick disk is much shorter than that of the thin disk. A thick disk
scale-length of L_{thick}=2.0 kpc, and L_{thin}=3.8 kpc for the thin disk,
better match the data.
View original:
http://arxiv.org/abs/1201.2009
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