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Session 14 - Milky Way Galaxy.
Display session, Monday, January 15
North Banquet Hall, Convention Center
We present radial velocities, metallicity estimates, and photometric parallaxes for a sample of 189 stars in a field at (l,b) = (8.4^\circ, -6.0^\circ). We use the derived distances to weed out stars in our sample which are likely to be in the foreground disk, then determine the rotational kinematics of the bulge from the remainder of the sample. We show that the mean rotation speed in our field is higher than predicted by models of galactic structure which include an oblate, isotropic bulge -- the higher mean galactocentric rotation is consistent with models which have a central bar. In contrast to recent studies, we find that once metallicity-dependent sampling biases are removed, there is little or no indication that the kinematics of the bulge stars correlate with metallicity. Overall abundances are in accord with those found in Baade's Window and so suggest that there is no longitudinal abundance gradient in the bulge.
Program listing for Monday