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

A deep K-s-band photometric catalogue of galaxies at the core of the rich, nearby Norma cluster (ACO3627) is presented. The survey covers about 45 x 45 arcmin(2) (slightly less than 1/3 Abell radius), which corresponds to similar to 0.8h(70)(-2) Mpc(2) at the adopted distance (upsilon(CMB)/H-0) of 70h(70)(-1) Mpc of this cluster. The survey is estimated to be complete to a magnitude of M-Ks less than or similar to -19.5 mag. This extends into the dwarf regime, 6 mag below M-Ks*. 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 M-Ks* = -25.39 +/- 0.80 mag and faint-end slope of alpha =-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.