RSAA Colloquia / Seminars / Feast-of-Facts: Tuesday, 12 December 2017, 11:00-12:00; Duffield Lecture Theatre

Srinivasan Raghunathan

"Measuring masses of galaxy clusters using CMB-cluster lensing"

Galaxy clusters are the largest gravitationally bound objects in the Universe and are excellent cosmological probes. Their power as cosmological probes, however, is currently limited by the systematics involved in the measurement of their mass. In this talk, I will discuss the method to estimate their masses using the weak-gravitational lensing of the Cosmic Microwave Background (CMB). I will explain the systematics involved in the measurements and the importance of using CMB polarisation data in the future. Finally I will discuss the uncertainties in the mass estimates for the current CMB experiments and provide realistic forecasts for the CMB-S3/S4 experiments. Reference: arXiv: 1705.00411