Hydrodynamical simulations of the Sunyaev–Zel'dovich effect: cluster scaling relations and X-ray properties

The Sunyaev–Zel'dovich (SZ) effect is a powerful new tool for finding and studying clusters at high redshift, particularly in combination with their X-ray properties. In this paper we quantify the expected scaling relations between these properties using numerical simulations with various models for heating and cooling of the cluster gas. For a Non-radiative model, we find scaling relations in good agreement with self-similar predictions: Y∝T5/2X and Y∝L5/4X. Our main results focus on predictions from Cooling and Preheating simulations, shown recently by Muanwong et al. to provide a good match to the X-ray scaling relations at z= 0. For these runs, we find slopes of approximately Y∝T3X and Y∝LX, steeper and flatter than the self-similar scalings respectively. We also study the redshift evolution of the scaling relations, and find that the slopes show no evidence of evolution out to redshifts well beyond unity, while the normalizations of relations between the SZ signal and X-ray properties do show evolution relative to that expected from self-similarity, particularly at z < 1