AN AXISYMMETRICAL DISTRIBUTION FUNCTION FOR THE GALACTIC BULGE

We describe a method for parameterizing two-integral distribution functions, based on triangular tessellations of the integral plane. We apply the method to the axisymmetric isotropic rotator model for the Galactic bulge of Kent (1992), and compute the projected distributions of radial velocities and proper motions expected for this model in order to allow a detailed comparison with observations. This type of analysis yields complete model predictions, significantly stronger than the velocity moments that can be calculated from the Jeans equations. In spite of strong evidence from surface photometry and from study of the gas kinematics that the Galactic bulge is not axisymmetric, the stellar kinematics in Baade's window art very similar to those of an isotropic oblate rotator.