Point Sources in the Context of Future SZ Surveys

Abstract

We look at the impact of infrared (IR) and radio point sources on upcoming large-yield Sunyaev-Zel'dovich (SZ) cluster surveys such as those to be undertaken by the Atacama Pathfinder Experiment (APEX), the South Pole Telescope (SPT), and the Atacama Cosmology Telescope (ACT). The IR and radio point-source counts are based on observations by the Submillimeter Common-User Bolometric Array (SCUBA) and the Wilkinson Microwave Anisotropy Probe (WMAP) instruments, respectively. We show that the contributions from IR-source counts, when extrapolated from the SCUBA frequency of 350 GHz to the operating frequencies of these surveys (~100-300 GHz), can be a significant source of additional noise, which needs to be accounted for in order to extract the optimal science from these surveys. 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 40 GHz, but is comparable to the IR near 200 GHz. However, the radio signal may be correlated with clusters of galaxies and have a disproportionately larger effect.