Clustering and Dynamics in a Dissipative CDM N-Body Simulation

An N-body code is used to follow the evolution of an Ω = 1, h = 0.5 Cold Dark Matter spectrum in cubes of 40, 80 and 200 Mpc on a side. We model a universe consisting of collisionless dark matter and a dissipative baryonic component. Cooling enables gas particles to congregate into small groups which are then identified as galaxies. The the bias present in the model, at the time identified as the present, is relatively small; b = 1.3 ± 0.2. The pairwise velocities on small scales are a factor of two smaller in the galaxies than in the dark matter. Estimates of the mass density of the Universe derived from the Cosmic Virial Theorem and from virial analysis of groups gives Ω ~ 0.2.