Statistics of Sunyaev-Zel'dovich cluster surveys

Abstract

We describe a detailed analytic model for predicting statistical quantities (such as number counts, redshift distributions and sizes) of clusters detected in blank-field, thermal Sunyaev–Zel'dovich effect experiments. We include in this model the possibility of non-Gaussian density perturbations in the early Universe and also describe a simple model for the effects of preheating on cluster Sunyaev–Zel'dovich effect fluxes. We use this model to explore the current state of the theoretical uncertainties present in this type of analytic modelling, highlighting where further improvement will be necessary to exploit forthcoming surveys fully. We then go on to explore the constraints on cosmological parameters, the presence of any non-Gaussianity and the degree of cluster preheating that may be obtained from both the Bolocam and Planck experiments. We find that, providing redshifts can be measured for all detected clusters, the Bolocam experiment may provide detections of non-Gaussianity or preheating and could give approximate measurements of these effects if prior knowledge of the various cosmological parameters is taken into account. The Planck experiment Sunyaev–Zel'dovich effect cluster survey is predicted to provide highly accurate (∼5 per cent) measurements of the degree of non-Gaussianity and preheating while also providing measurements of several cosmological parameters to accuracies of a few per cent independently of those constraints that will be derived from its detections of primordial cosmic microwave background anisotropies.