Expectations for an Interferometric Sunyaev‐Zeldovich Effect Survey for Galaxy Clusters

Abstract

We estimate the expected yield of a nontargeted survey for galaxy clusters using the Sunyaev-Zeldovich effect (SZE). Estimating survey yields requires a detailed model for both cluster properties and the survey strategy. We address this by making mock observations of galaxy clusters in cosmological hydrodynamical simulations. The mock observatory consists of an interferometric array of ten 2.5 m diameter telescopes, operating at a central frequency of 30 GHz with a bandwidth of 8 GHz. For a survey covering 1 deg2 per month, we find that clusters with a mass above 2.5 × 1014 h M☉ will be detected at any redshift, with the exact limit showing a modest redshift dependence. Using a Press-Schechter prescription for evolving the number densities of clusters with redshift, we determine that such a survey should find hundreds of galaxy clusters per year, many at high redshifts and relatively low mass—an important regime uniquely accessible to SZE surveys. Currently favored cosmological models predict ~25 clusters per deg2.