A measurement of CMB cluster lensing with SPT and DES year 1 data

Abstract

Clusters of galaxies gravitationally lens the cosmic microwave background\n(CMB) radiation, resulting in a distinct imprint in the CMB on arcminute\nscales. Measurement of this effect offers a promising way to constrain the\nmasses of galaxy clusters, particularly those at high redshift. We use CMB maps\nfrom the South Pole Telescope Sunyaev-Zel'dovich (SZ) survey to measure the CMB\nlensing signal around galaxy clusters identified in optical imaging from first\nyear observations of the Dark Energy Survey. The cluster catalog used in this\nanalysis contains 3697 members with mean redshift of $\\bar{z} = 0.45$. We\ndetect lensing of the CMB by the galaxy clusters at $8.1\\sigma$ significance.\nUsing the measured lensing signal, we constrain the amplitude of the relation\nbetween cluster mass and optical richness to roughly $17\\%$ precision, finding\ngood agreement with recent constraints obtained with galaxy lensing. The error\nbudget is dominated by statistical noise but includes significant contributions\nfrom systematic biases due to the thermal SZ effect and cluster miscentering.\n