NON-EXTENSIVE THERMOSTATISTICAL APPROACH OF THE PECULIAR VELOCITY FUNCTION OF GALAXY CLUSTERS

We show that the observational data recently provided by Giovanelli el al. and discussed by Bahcall and Oh concerning the velocity distribut ion of clusters of galaxies can be naturally fitted by a statistical d istribution which generalizes the Maxwell-Boltzmann one (herein recove red for the entropic index q = 1). Indeed a recent generalization of t he Boltzmann-Gibbs thermostatistics suggests for this problem that the probability Function is given, within a simple phenomenological model , by [GRAPHICS] A remarkably good fitting with the data is obtained fo r q = 0.23(-0.05)(+0.07) and upsilon(0) = 490 +/- 5 km s(-1).