The Galactic Thick Disk: Near and Far
Carlos Allende Prieto (Texas)
The Milky Way's second disk was first identified in star counts
some 20 years ago. The thick disk has a stellar density of just
4% of the thin disk, and it contains relatively metal-poor, very
old, stars that revolve around the Galactic center significantly
slower than those in the thin disk. Recent spectroscopic surveys
have targeted thick-disk stars in the solar vicinity --at high
spectral resolution, and several kpc from the plane --at low
resolution. These new data offer invaluable clues as to where the
thick disk fits in the history of the Galaxy.
