Dynamically stable models for galaxies

A popular approach to model galaxies is Schwarzschild's method. For this method, a grid of sample orbits of stars in an external potential is calculated, and a model for the stellar system is obtained through attributing specific weights to the orbits in a superposition of them. The models created with Schwarzschild's method can fit many observed properties of the modeled stellar system with high precision. However, systems that are stationary as Schwarzschild models may therefore exhibit a strong time evolution if they are translated into more realistic self-gravitating models. The issue is highlighted with the Galactic center as an example.