Diffuse Light in A2670: Smoothly Distributed?

Abstract

We report R- and V-band observations of the rich cluster of galaxies A2670. A measurement of the circular component of the diffuse light or halo of the cD follows a smooth de Vaucouleurs profile out to 230/h kpc. Measurements of the fluctuation per pixel indicate that the diffuse light is likely to be composed of numerous low-luminosity objects. Autocorrelations of the residual images allow us to probe the small-scale fluctuations to a sensitivity of 0.05% of the diffuse light. A differential luminosity function of the central 160/h kpc suggests real differences in the luminosity function within the cluster center from a universal cluster luminosity function. We measure the V - R color of the cD and cluster galaxies and the color gradient across the halo. Also, we report results from a search for detecting evidence of the visible results of dynamical friction, that is, the wakes associated with galaxies passing through a diffuse medium.