Galaxy Clusters Selected by the Sunyaev-Zel'dovich Effect in the SPT-3G Main Survey

One of the key objectives of high resolution mm-wave surveys has been the construction of mass-limited samples of galaxy clusters identified via the thermal Sunyaev- Zel'dovich (SZ) effect, through which massive clusters imprint subtle temperature distortions on the cosmic microwave background. The abundance of such clusters is a powerful cosmological probe as it depends sensitively upon both the expansion history of the universe and the growth of density fluctuations. In this talk I will discuss a new cluster sample produced from 5 years of data in the 1600-sq-degree SPT-3G main survey. The sample contains over 7,000 confirmed SZ clusters, including >1,000 above redshift z=1. I will also highlight progress towards obtaining cosmological results from this sample using a combination of weak lensing data from the Dark Energy Survey and new cosmological simulations.