Point sources in the context of future SZ surveys

Abstract

We look at the impact of Infra-Red (IR) and radio point sources on upcoming large yield Sunyaev-Zel'dovich (SZ) cluster surveys such as APEX, SPT and ACT. The IR and radio point source counts are based on observations by the the SCUBA and WMAP instruments respectively. We show that the contributions from IR source counts, when extrapolated from the SCUBA frequency of 350GHz to the operating frequencies of these surveys (~100-300GHz), can be a significant source of additional `noise' which needs to be accounted for in order to extract the optimal science from these surveys. Alternatively, these surveys give us an opportunity to study IR sources, their numbers and clustering properties, opening a new window to the high redshift universe. For the radio point sources, the contribution depends on a more uncertain extrapolation from 40GHz but is comparable to the IR near 200GHz. However, the radio signal may be correlated with clusters of galaxies and have a disproportionately larger effect.