Phase densities and the merger hypothesis

The question of whether NGC 5813 and IC 1459 are merger remnants is addressed, and it is shown that these galaxies have peak phase densities that are normal for elliptical galaxies of their luminosity. Central phase densities are determined for ellipticals and for two models of exponential disks. It is demonstrated that the distribution function of an elliptical galaxy displays a higher degree of mixing than that of a constant scale-height exponential disk, consistent with the merger hypothesis. The results suggest that the merger of pure disk galaxies may produce ellipticals. 31 refs