The spatial distribution of nearby galaxy clusters in the northern and southern galactic hemispheres

We compare the spatial distributions of galaxy clusters in the northern and southern galactic hemispheres, and the Abell and ACO clusters distributions. We perform a statistical (correlation and cluster) analysis of a sample of Abell and ACO galaxy clusters in the southern galactic hemisphere (bII ≤ −40 ◦ and m10 ≤ 16.5). We compare these results with a symmetric sample (bII ≥ +40 ◦ and m10 ≤ 16.5) at northern galactic latitude taken from Postman et al. (1992). For the northern sample, we substantially confirm the results of Postman et al. We find that the two-point spatial correlation function ξcc(r) of northern and southern clusters is comparable, with mean correlation length r0 ∼ 19.6 h −1 Mpc and slope γ ∼ -1.8. Moreover, ACO and Abell clusters show similar spatial correlations. ξcc(r) is positive up to ∼ 45 h −1 Mpc in all our samples, and it is systematically negative in the range 50 <∼ r <∼ 100 h −1 Mpc. Percolation properties are remarkably similar in the northern and southern cluster samples. We give also a catalog of superclusters. In the south galactic hemisphere the main feature is a very rich, extended supercluster (spreading over ∼ 65 h Mpc) in the Horologium region at a redshift z ∼ 0.06, near to a large void.