Kinematics of Bulge Giants in F588

Radial velocities for 331 stars in the F588 bulge field at 1, b = (80, 70) are obtained. The mean Galactocentric velocity for 319 stars with R - 1. 0) are = 65. 9 + 5. 1 km s 1 and q = 71. 9 + 3. 6 km 1 The difference between halo and bulge kinematics is of very high statistical significance. The Galactic bulge and halo are distinct components, defined by consistency among Fe/H, V, and Cr. Bulge giants are also found to have their kinematics correlated with their metallicities. After discussing other possible causes, including disk and halo contamination, it is argued that this effect is real. The kinematics of 26 M giants in our sample are compared with those of other evolved bulge tracers (Mira variables, OH/IR stars, SiO masers, etc. ). These M giants observed in the field have kinematics consistent with their being bulge members. The dependence of velocity dispersion on distance from the Galactic center is determined by combining the data with existing data from Baade's window. While the line-of-sight velocity dispersion of the bulge giants decreases steeply with distance from the Galactic center, that of halo giants decreases very slowly if at - all. The mass in the inner 1. 5 kpc is determined to be M₁ ₅ = (1. 38 + 0. 26) x 1010 M₀ and M₁ ₅ = (1. 74 + 0. 28) x 1010 M₀ for the cases of isotropic and anisotropic inner halo, respectively. On the basis of kinematics and metallicities, we conclude that the bulge is a distinct galactic component and not the inner extension of the halo, thin disk, or thick disk.