The Stability of Axisymmetric Galaxy Models with Anisotropic Dispersions

Abstract

The possible equilibrium configurations for elliptical galaxies and the bulges of spiral galaxies are no longer thought to be confined to the small class of axisymmetric systems with isotropic velocity dispersions. Many of these systems are not supported by rotation but instead by anisotropic velocity dispersions which are maintained by nonclassical integrals of motion (e.g., Binney 1978), and may be triaxial. Few theoretical models for such systems exist (Schwarzschild 1981). Here we discuss some axisymmetric models that we have constructed by means of Schwarzschild's (1979) selfconsistent method, and in particular their stability.