Galaxy Clusters from the DESI Legacy Imaging Surveys. I. Cluster Detection

Based on the photometric redshift catalog of Zou et al., we apply a fast clustering algorithm to identify 540,432 galaxy clusters at z less than or similar to 1 in the DESI legacy imaging surveys, which cover a sky area of about 20,000 deg(2). Monte Carlo simulations indicate that the false-detection rate of our detecting method is about 3.1%. The total masses of galaxy clusters are derived using a calibrated richness-mass relation that is based on the observations of X-ray emission and the Sunyaev and Zel'dovich effect. The median redshift and mass of our detected clusters are about 0.53 and 1.23 x 10(14) M, respectively. Comparing with previous clusters identified using the data of the Sloan Digital Sky Survey; we can recognize most of them, especially those with high richness. Our catalog will be used for further statistical studies on galaxy clusters and environmental effects on galaxy evolution, etc.

Automated summary

The study identified approximately 540,432 galaxy clusters with a redshift less than or equal to 1 based on the DESI legacy imaging surveys, using a calibrated richness-mass relation derived from observations. The median redshift and mass of the detected clusters were about 0.53 and 1.23 x 10^14 solar masses, respectively. Comparison with clusters identified using Sloan Digital Sky Survey data showed that most clusters, especially those with high richness, were recognized. The catalog will be used for further statistical studies on galaxy clusters and environmental effects on galaxy evolution.