  New information on the relations between the Galactic disks, the halo, and
satellite galaxies is being obtained from elemental abundances of stars having
metallicities in the range -1.5 < [Fe/H] < -0.5. The first results for a sample
of 26 halo stars and 13 thick-disk stars observed with the ESO VLT/UVES
spectrograph are presented. The halo stars fall in two distinct groups: One
group (9 stars) has [alpha/Fe]= 0.30 +-0.03 like the thick-disk stars. The
other group (17 stars) shows a clearly deviating trend ranging from [alpha/Fe]=
0.20 at [Fe/H]= -1.3 to [alpha/Fe]= 0.08 at [Fe/H]= -0.8. The kinematics of the
stars are discussed and the abundance ratios Na/Fe, Ni/Fe, Cu/Fe and Ba/Y are
applied to see if the low-alpha stars are connected to the thin disk or to
Milky Way satellite galaxies. Furthermore, we compare our data with simulations
of chemical abundance distributions in hierarchically formed stellar halos in a
LambdaCDM Universe.

Astrophysics