Dissipationless galaxy formation and the R to the 1/4-power law

A variety of irregular initial conditions are used in collision-free N-body simulations of the collapse phase of galaxy formation, producing density distributions that are in good agreement with the r to the 1/4-power law when the collapse factor is large. Agreement holds for a region between radii containing 10-99% of the total mass in the r to the 1/4-power model, corresponding to a surface brightness range of 12 mag. In the equilibrium configurations, the central densities are larger than initial densities by a factor of 1000. The envelopes of the final models have a strongly anisotropic velocity distribution.