A DECADE of Giants: A catalog of 42,000 optically identified galaxy clusters from 13,000 $\mathrm{deg}^2$ of the sky

Abstract

Galaxy clusters are sensitive to a rich variety of physics spanning a wide dynamic range, from microphysical to cosmological scales. Optical datasets are efficient at identifying clusters and studying their properties. We leverage 13,000 $\rm deg^2$ of the sky imaged by the Dark Energy Camera (DECam) and extract over 40,000 clusters using the redMaPPer algorithm. Our catalog spans $0.2 < z < 0.9$ and $M_{\rm 200c} \gtrsim 10^{14} {\rm M}_{\odot}/h$, with four-band ($griz$) photometric redshifts that have a precision $σ_z/(1 + z) \leq 0.008$ below $z < 0.65$, and $\leq 0.011$ between $0.65 < z < 0.9$ and that exhibit an outlier rate of $f_{\rm out} < 0.2\%$. Our cluster finding is calibrated using spectroscopic data, but we find that a larger spectroscopic sample does not improve the performance of our cluster redshift estimation. We cross-match our catalog to those produced from millimeter-wave and X-ray data, and extract scaling relations between various cluster observables. There is excellent agreement between our estimates for different subsets of the 13,000 ${\rm deg}^2$ dataset, and also with results from prior catalogs and simulations. We use our joint analysis of millimeter-wave and optical data to estimate the halo masses of individual clusters. We also provide lensing profiles, measured for each cluster using overlapping galaxy shape catalogs, to enable additional mass-calibration work from the community. We demonstrate from a suite of tests that spatial inhomogeneity in the quality of the imaging data does not have an appreciable impact on the properties of this catalog. We also test a cylindrical richness observable, which is defined such that it is significantly simpler to model, and show that it has precision competitive with the traditional optical richness observable. All data products and measurements are made publicly available.