Color distributions in early-type galaxies. II - Eight ellipticals in the Virgo cluster

The authors have obtained high-precision surface-brightness measurements in three colors of eight early-type galaxies in the Virgo cluster using a scanning CCD. The total luminosities of the galaxies in this sample span a range of 8 mag. The isophotes of each of the galaxies have been fit to a model consisting of a sequence of concentric ellipses. The parameters determined from the fit are surface brightness, colors, ellipticity, and position angle as functions of radius. Analysis of these isophotal parameters yields conclusions which are discussed in detail. In this sample there is a continuous sequence of departure from a de Vaucouleurs law profile for elliptical galaxies, with high-luminosity systems having outer envelopes above a fit to the inner regions and low-luminosity systems having less light in their outer regions than the fit.