2002ApJ...579...93P

We have conducted an automated search for galaxy clusters within a contiguous 16 deg² I-band survey in the north Galactic hemisphere. A matched filter detection algorithm identifies 444 cluster candidates in the range 0.2≲z≲1.2. The full catalog is presented along with the results from a follow-up spectroscopic survey. The estimated redshift distribution of the cluster candidates is consistent with a constant comoving density over the range 0.2≤z_est≤0.8. A decline in the cluster space density by more than a factor of 3 over this redshift range is rejected at the greater than 99.9% confidence level. We find that the space density of Λ_cl≥40 clusters in our survey lies in the range (1.6-1.8)x10^–5 h³₇₅Mpc^–3, ∼1.5 times higher than the local distribution of comparably rich Abell richness class ≥0 clusters. The Λ_cldistribution is consistent with a power law. The discrepancy between the space density of Abell clusters and the clusters in this survey declines quickly as Λ_clincreases, suggesting that the difference at lower richness is due to significant incompleteness in the Abell catalog. A percolation analysis reveals that 10%-20% of the spectroscopically confirmed distant clusters are linked into superclusters at overdensities between 10<δρ/ρ<50, similar to what is seen in the local cluster distribution. This suggests that there has been little evolution of the cluster-cluster correlation length for z≲0.5.