The Universality of the Fundamental Plane of E and S0 Galaxies. Sample Definition and I Band Photometric Data

Abstract

As part of a project to compare the Fundamental Plane and Tully-Fisher distance-scales, we present here I band CCD photometry for 636 early-type galaxies in 8 clusters and groups of galaxies. These are the A262, A1367, Coma (A1656), A2634, Cancer and Pegasus clusters, and the NGC 383 and NGC 507 groups. Sample selection, cluster properties, and cluster membership assignment criteria are discussed. We present photometric parameters that are used in the Fundamental Plane relation, the effective radius r_e and the effective surface brightness mu_e, as derived from a r^{1/4} fit to the observed radial photometric profile of each galaxy. A comparison with similar data found in the literature for the Coma cluster shows that large systematic uncertainties can be introduced in the measurement of r_e and mu_e by the particular method used to derive those parameters. However the particular combination of these two parameters that enters in the Fundamental Plane relation is a quantity that can be measured with high accuracy.