Two new catalogues of superclusters of Abell/ACO galaxy clusters out to redshift 0.15

Abstract

We present two new catalogues of superclusters of galaxies out to a redshift of z = 0.15, based on the Abell/ACO cluster redshift compilation maintained by one of us (HA). The first of these catalogues, the all-sky Main SuperCluster Catalogue (MSCC), is based on only the rich (A-) Abell clusters, and the second one, the Southern SuperCluster Catalogue (SSCC), covers declinations δ < -17° and includes the supplementary Abell S-clusters. A tunable Friendsof- Friends algorithm was used to account for the cluster density decreasing with redshift and for different selection functions in distinct areas of the sky. We present the full list of Abell clusters used, together with their redshifts and supercluster memberships and including the isolated clusters. The SSCC contains about twice the number of superclusters than MSCC for δ < -17°, which we found to be due to (1) new superclusters formed by A-clusters in their cores and surrounded by S-clusters (50 per cent), (2) new superclusters formed by S-clusters only (40 per cent), (3) redistribution of member clusters by fragmentation of rich (multiplicity m>15) superclusters (8 per cent), and (4) new superclusters formed by the connection of A-clusters through bridges of S-clusters (2 per cent). Power-law fits to the cumulative supercluster multiplicity function yield slopes of a = -2.0 and α = -1.9 for MSCC and SSCC, respectively. This power-law behaviour is in agreement with the findings for other observational samples of superclusters, but not with that of catalogues based on cosmological simulations.