Cluster Catalog Validation with Multiwavelength Data

Abstract The Legacy Survey of Space and Time will provide a ground-breaking data set for cosmology, but to achieve the precision needed, the data, data reduction, and algorithms measuring the cosmological data vectors must be thoroughly validated and calibrated. In this note, we focus on clusters of galaxies and present a set of validation tests for optical cluster finding algorithms through comparison to X-ray and Sunyaev–Zel’dovich effect data. As an example, we apply our pipeline to compare the performance of the red-sequence Matched filter Probabilistic Percolation and Wavelet Z Photometric cluster finding algorithms on Dark Energy Survey data. We investigate metrics of completeness, centering, and scaling relations. We find more than 88% of South Pole Telescope clusters with both algorithms, and 8% or fewer of the clusters are found to be miscentered. The intrinsic scatter in both samples is low compared to X-ray temperature.