The Norma cluster (ACO3627): II. The near infrared K_s-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 by 45
square arcmin (slightly less than 1/3 Abell radius), which corresponds to
approx. 0.8 Mpc^2 at the adopted distance (v_cmb/H0) of 70 Mpc of this cluster.
The survey is estimated to be complete to a magnitude of M_Ks <~ -19.5 mag.
This extends into the dwarf regime, 6 magnitudes 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 \pm 0.80 mag and faint-end
slope of alpha = -1.26 \pm 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 both the shape of the bright end and the faint end slope
are relatively insensitive to environment.
