The First Galaxy Cluster Catalog from the SPT-3G 1500 deg² Survey

Because the formation history of galaxy clusters is expected to have strongly depended on the universe's physical conditions through time, measuring the abundance, richness, and redshifts of galaxy clusters provides a unique way to probe the universe’s large-scale structure and underlying physics across cosmic timescales. High-resolution (arcminute-scale) cosmic microwave background (CMB) surveys are capable of detecting galaxy clusters across all redshifts due to a CMB scattering process known as the Sunyaev-Zeldovich (SZ) effect. This effect occurs when CMB photons inverse-Compton scatter off energetic, ionized particles present in the clusters, thereby resulting in arcminute-scale intensity distortions in the CMB at locations where galaxy clusters exist. I will present a first catalog of SZ-selected galaxy clusters from an analysis of two years of data from the SPT-3G 1500 deg² CMB survey, and also forecast expected improvements from the full multiyear SPT-3G dataset.  These cluster catalogs will contribute towards improved cosmological constraints on models of dark energy, modified gravity, and neutrino mass.