Galaxy velocity dispersions using a cross-correlation method

A cross-correlation method for measuring velocity dispersions, introduced by Tonry and Davis (1979) and used for measuring velocity dispersions for 350 elliptical galaxies, is modified. The resulting technique is used to tabulate central velocity dispersions for 79 additional early-type galaxies, and various tests of the effects of random and systematic errors are carried out to establish the accuracy of the results. A significant difference between the present cross-correlation technique and that proposed by Tonry and Davis is described. 20 refs.