Abstract: Observations of the cosmic microwave background (CMB) form the pillar of our current understanding of cosmology. Measurements of the temperature and polarization anisotropies of the CMB extending to small angular scales set tight constraints on cosmological parameters, probing both the standard LCDM model and the physics of inflation. Making these exquisitely precise measurements requires building increasingly sensitive instruments with larger focal plane areas and greater detector counts.

SPT-3G is the latest instrument installed on the South Pole Telescope, and it will map the CMB at 95, 150, and 220 GHz with ~16,000 detectors, a tenfold increase in detector count over its predecessor. In 2018, SPT-3G began a multiyear survey of a 1500 sq. deg. patch of sky that will produce maps with an unprecedented combination of depth and angular resolution, improving current constraints on the high-ell CMB power spectrum by over an order of magnitude.

In this talk I will discuss the SPT-3G instrument and current status of the 1500 sq. deg. survey, as well as an analysis of data taken in 2018 to produce a measurement of the E-mode polarization and temperature-E-mode correlation power spectra of the CMB.