SIMBAD references

Deep photometric observations in three colours of the cluster A 496 show that the luminosity function is bimodal with a deep gap at g∼19.0. That is there is a net separation between E/SO galaxies that are nicely fitted by a gaussian distribution curve and the dwarfs that better match a Shechter function. This is the first cluster observed and reduced out of a sample of 19 clusters which we have in our program. However comparison with the data of Virgo and Coma might suggest a correlation between cluster morphology and amplitude of the two distributions: normal and dwarf population. This would have strong implication for the understanding of cluster formation and evolution so that we are pursuing the estimate of the LF in various colours and to faint magnitudes both for low and high redshift clusters.