Galaxy Luminosity Functions in WINGS clusters
  Using V band photometry of the WINGS survey, we derive galaxy luminosity
functions (LF) in nearby clusters. This sample is complete down to Mv=-15.15,
and it is homogeneous, thus allowing the study of an unbiased sample of
clusters with different characteristics. We constructed the photometric LF for
72 out of the original 76 WINGS clusters, excluding only those without a
velocity dispersion estimate. For each cluster we obtained the LF for galaxies
in a region of radius=0.5 x r200, and fitted them with single and double
Schechter's functions. We also derive the composite LF for the entire sample,
and those pertaining to different morphological classes. Finally we derive the
spectroscopic cumulative LF for 2009 galaxies that are cluster members. The
double Schechter fit parameters are neither correlated with the cluster
velocity dispersion, nor with the X-ray luminosity. Our median values of the
Schechter's fit slope are, on average, in agreement with measurements of nearby
clusters, but are less steep that those derived from large surveys, such as the
SDSS. Early--type galaxies outnumber late-types at all magnitudes, but both
early and late types contribute equally to the faint end of the LF. Finally,
the spectroscopic LF is in excellent agreement with the ones derived for A2199,
A85 and Virgo, and with the photometric one at the bright magnitudes (where
both are available). There is a large spread in the LF of different clusters.
However, this spread is not caused by correlation of the LF shape with cluster
characteristics such as X--ray luminosity or velocity dispersions. The faint
end is flatter than what previously derived (alpha_f=-1.7) at odds with what
predicted from numerical simulations.
