Nuclear Disks Embedded in Elliptical Galaxies

Extract

The Hubble Space Telescope has discovered a number of ellipticals and S0's with small nuclear, stellar disks (eg. van den Bosch et al. 1994, AJ, 108, 1579). The kinematics of these disks may allow a derivation of the central mass density of the host galaxy, in much the same way as is possible with ionized gas disks (e.g. M87; Harms et al. 1994, ApJ, 435, L35). In order to understand the kinematic signatures of these disks, we have constructed two-integral, axisymmetric models of ellipticals with nuclear stellar disks. We use the method developed by Hunter & Qian (1993, MNRAS, 262, 401) to calculate f(E, L_z ), from which we derive the velocity profiles (VPs). Depending on the choice of the odd part of the DF, one can construct a large variety of models including some with counter-rotating cores.