  The detection of clusters of galaxies in large surveys plays an important
part in extragalactic astronomy, and particularly in cosmology, since cluster
counts can give strong constraints on cosmological parameters. X-ray imaging is
in particular a reliable means to discover new clusters, and large X-ray
surveys are now available. Considering XMM-Newton data for a sample of 40 Abell
clusters, we show that their analysis with a Kolmogorov distribution can
provide a distinctive signature for galaxy clusters. The Kolmogorov method is
sensitive to the correlations in the cluster X-ray properties and can therefore
be used for their identification, thus allowing to search reliably for clusters
in a simple way.
