Joint Astrophysics Colloquium

Cluster Detection in SZ Surveys

Laurie Shaw

McGill

Measurements of the mass and redshift distribution of clusters of galaxies will provide us with one of the most promising means of constraining cosmological parameters. Upcoming Sunyaev-Zel'dovich experiments — such as the South Pole Telescope — aim to survey a large fraction of the sky searching for clusters via their SZ imprint on the CMB. In order to improve existing constraints, it is vitally important that we are able to detect and accurately infer the mass of large sample clusters via measurements of their integrated SZ flux. In the first part of this talk I will review large-scale structure formation in the Universe, and the cosmological dependence of the cluster mass-function. I will then describe work being done to evaluate the effectiveness of cluster detection techniques in SZ images, using synthetic SZ sky maps produced from state-of-the-art cosmological simulations. Specifically, I will demonstrate how we might achieve accurate measures of cluster masses and investigate how catalogue completeness and purity can be improved via careful cross-matching between SZ and optical cluster surveys.