Dissipative formation of an elliptical galaxy

The formation of elliptical galaxies is modeled using a simple scheme of gas cloud collisions incorporated into a restricted N-body code. The protogalaxies are required to be largely self-gravitating in order to give rise to a strongly anisotropic model galaxy. It is then expected that the ratio of dark material to gas varies from place to place, ellipticals arising in regions where gas has been piled up to dominate the dark matter. During collapse, gas pressure exerts considerable force, which leaves observable traces in the dynamical and chemical properties of the final model galaxies. The latter are found to be generally compatible with the observed properties of elliptical galaxies.