Constructing stellar dynamic models for elliptical galaxies

Chris Hunter

We review methods for constructing steady-state stellar dynamic models, both axisymmetric and triaxial. Models need to be capable of matching the increasing amount of kinematic and other observational data that is now becoming available. To date, several elliptical galaxies have been well fitted by axisymmetric models. Some of these are galaxies which are believed to have central black holes, because of the interest in providing constraints on the masses of those black holes.

Methods are available for constructing triaxial galaxy models with smooth cores at their centers, though few models of real galaxies have been constructed. More effort has been directed at the more difficult problem of constructing triaxial models with central cusps. Many of these models incorporate stochastic orbits, and hence are not truly steady.

Spectral methods provide a means of greatly improving the accuracy which Schwarzschild's orbit superposition method can attain for galaxy models composed of regular orbits.