THE BULGE RADIAL VELOCITY ASSAY (BRAVA). I. SAMPLE SELECTION AND A ROTATION CURVE

Results from the ongoing Bulge Radial Velocity Assay ( BRAVA) are presented. BRAVA uses M red giant stars, selected from the 2MASS catalog to lie within a bound of reddening-corrected color and luminosity, as targets for the Cerro Tololo Inter-American Observatory 4 m Hydra multiobject spectrograph. Three years of observations investigate the kinematics of the Galactic bulge major (-10 degrees < l < + 10 degrees, b = -4 degrees) and minor (-6 degrees < b < +5 degrees, -0.4 degrees < l < 0.0 degrees) axes with similar to 3300 radial velocities from 32 bulge fields and one disk field. We construct a longitude-velocity plot for the bulge stars and find that, contrary to previous studies, the bulge does not rotate as a solid body; from -4 degrees < l < 4 degrees the rotation curve has a slope of roughly 100 km s(-1) kpc(-1) and flattens considerably at greater l, reaching a maximum rotation of 75 km s(-1). We compare our rotation curve and velocity dispersion profile both to the self-consistent model of Zhao and to N-body models; neither fits both our observed rotation curve and velocity dispersion profile. We place the bulge on the plot of V-max/sigma vs. epsilon and find that the bulge lies near the oblate rotator line and very close to the parameters of NGC 4565, an edge-on spiral galaxy with a bulge similar to that of the Milky Way. We find that our summed velocity distribution of bulge stars appears to be sampled from a Gaussian distribution, with sigma = 116 +/- 2 km s(-1) for our full data set. Two candidate cold streams are not confirmed with additional data.