The Norma cluster (ACO3627) - II. the near-infrared Ks-band luminosity function

Abstract

A deep Ks-band photometric catalogue of galaxies at the core of the rich, nearby Norma cluster (ACO3627) is presented. The survey covers about 45 × 45 arcmin2 (slightly less than 1/3 Abell radius), which corresponds to ∼0.8 h-270 Mpc2 at the adopted distance (vCMB/H0) of 70 h-170 Mpc of this cluster. The survey is estimated to be complete to a magnitude of. This extends into the dwarf regime, 6 mag below. The catalogue contains 390 objects, 235 of which are classified as likely or definite galaxies and 155 as candidate galaxies. The Ks-band luminosity function (LF) is constructed from the photometric sample, using a spectroscopic subsample to correct for fore and background contamination. We fit a Schechter function with a characteristic magnitude of and faint-end slope of α = -1.26 ± 0.10 to the data. The shape of the LF is similar to those found in previous determinations of the cluster LF, in both optical and near-infrared. The Schechter parameters agree well with those of recent field LFs, suggesting that the shape of both the bright-end and the faint-end slopes are relatively insensitive to environment. © 2009 RAS.