The luminosity function of galaxies in compact Groups(1).
HUNSBERGER S.D., CHARLTON J.C. and ZARITSKY D.
Abstract (from CDS):
From R-band images of 39 Hickson compact groups (HCGs), we use galaxy counts to determine a luminosity function extending to M_R_ = -14.0+5 log h75, approximately 2 mag deeper than previous compact group luminosity functions. We find that a single Schechter function is a poor fit χ2ν>4 to the data, so we fit a composite function consisting of separate Schechter functions for the bright and faint galaxies. The bright end is best fit with M* = -21.6 and α = -0.52, and the faint end with M* = -16.1 and α = -1.17. The decreasing bright-end slope implies a deficit of intermediate-luminosity galaxies in our sample of HCGs, and the faint-end slope is slightly steeper than that reported for earlier HCG luminosity functions. Furthermore, luminosity functions of subsets of our sample reveal more substantial dwarf populations for groups with X-ray halos, groups with tidal dwarf candidates, and groups with a dominant elliptical or lenticular galaxy. Collectively, these results support the hypothesis that within compact groups, the initial dwarf galaxy population is replenished by ``subsequent generations'' formed in the tidal debris of giant galaxy interactions.
Galaxies: Clusters: General - Galaxies: Luminosity Function, Mass Function - Galaxies: Photometry - X-Rays: Galaxies