Showing papers by "S. D. Hunsberger published in 1998"
TL;DR: In this article, the authors used galaxy counts to determine a luminosity function extending to MR = -14.0+5 log h75, approximately 2 mag deeper than previous compact group luminosity functions.
Abstract: From R-band images of 39 Hickson compact groups (HCGs), we use galaxy counts to determine a luminosity function extending to MR = -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 (χ$2{ν}$ -->$t SUPgt 2t/SUPgt t SUBgt {ν}t/SUBgt $ -->$t Igt tt/Igt SUPgt 2t/SUPgt t SUBgt {ν}t/SUBgt $ -->>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.
43 citations
TL;DR: In this paper, the authors used galaxy counts to determine a luminosity function extending to M_R=-14.0, approximately two magnitudes deeper than previous compact group luminosity functions.
Abstract: 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, approximately two magnitudes deeper than previous compact group luminosity functions. We find that a single Schechter function is a poor fit 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 alpha=-0.52 and the faint end with M^*=-16.1 and alpha=-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.
40 citations