SCALING INVARIANCE IN THE GALAXY DISTRIBUTION .2. SPATIAL AND LUMINOSITY EFFECTS

We analyze the variation of the galaxy clustering properties when either the luminosity range, the depth or the location in space, or the morphology class of the tested subsample varies. Although we examine these variations with the two-point correlation functions, we show that the results derived from them are difficult to interpret because of normalization problems. Thus, we rather concentrate on the (rescaled) void probability function, which is free of normalization effects and provides information of the high order properties of the statistics. We show that, in the CfA catalog, bright galaxies are more clustered than faint ones at the higher order of the statistics, although they both share the same correlation functions. We compare these results with the predictions of biased galaxy formation models. We confirm that elliptical and lenticular galaxies have a stronger two-point correlation function than spirals. But we show that both morphological classes do share the same high order statistics. We also compare the statistical properties of different samples of (bright) galaxies, with increasing depths. We confirm a variation of the correlation functions with the depth which is however completely normalization-dependent. We interpret it as due to morphological segregation, as well to the fact that different parts of the catalog are explored. Moreover, we show that all the samples (with different depths, locations, or morphological classes) do share almost indistinguishable high order statistics. This firmly confirms the existence of the scaling properties already established in the first paper in this series.