case western reserve university



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.