Weighing the giants with CMB lensing

Jan 22, 2019 - 11:00 am to 12:00 pm

Campus, Varian 355

Sanjay Patil (University of Melbourne)

Galaxy clusters are the largest virialized objects in the Universe, and are powerful probes of cosmology. Their abundance as a function of mass and redshift is extremely sensitive to how structures grow and the properties of dark energy. Though they are powerful probes of cosmology, they are currently limited by mass uncertainty which is ~ 15%. One way to measure cluster mass is through lensing of the cosmic microwave background (CMB). CMB-cluster lensing offers a robust and accurate way to constrain galaxy cluster masses, especially at high redshift (z > 1) where optical lensing measurements are challenging. With CMB lensing we expect to improve mass uncertainty to 3% for upcoming experiments such as AdVACT, SPT-3G etc., and to 1% for next-generation CMB experiments. In this talk, I will report on a demonstration of this technique using CMB data from the South Pole Telescope (SPT) to constrain masses of the Dark Energy Survey (DES) galaxy cluster catalog.