The Properties of Satellite Galaxies in External Systems. II. Photometry and Colors

Abstract

In this second paper dedicated to the study of satellite galaxies we present broad-band photometry in the B, V, R and I filters of 49 satellite galaxies orbiting giant isolated spiral galaxies. First analysis of the properties of these objects are presented by means of color--color and color--magnitude diagrams for early- and late-type satellites. Although we find differences in the slope of the V-I vs. Mv color magnitude diagram, as a whole, the relations are in agreement with the trends known to date for galaxies of similar magnitudes in nearby clusters of galaxies. Comparison with the relations found for satellites in the Local Group allows us to sample better the bright end of the luminosity function of satellite galaxies and extends for brighter objects the validity of the color--magnitude relation found for dwarf galaxies in the Local Group. Most of the E/S0 galaxies in our sample show a negative color gradient with values similar to those known for early type galaxies in other environments.