NEURAL-NETWORK METHOD FOR GALAXY CLASSIFICATION - THE LUMINOSITY FUNCTION OF E SO IN CLUSTERS/

We present a method based on the non-linear behaviour of neural networ k for the identification of the early-type population in the cores of galaxy clusters. A Kohonen Self Organising Map applied on a three-colo ur photometric catalogue of objects enabled us to select in each passb and the elliptical galaxies. We measured in this way the luminosity fu nction of the E/S0 galaxies selected in this way. Such luminosity func tions show peculiarities which disfavour the hypothesis of its univers ality often claimed for rich clusters and that can be related to the p ast dynamical history of the cluster as a whole.