An SZ Temperature Decrement - X-ray Luminosity Relation for Galaxy Clusters

Abstract

We present the observed relation between the cosmic microwave background (CMB) temperature decrement due to the Sunyaev-Zeldovich (SZ) effect and the X-ray luminosity of galaxy clusters. We discuss this relation in terms of the cluster properties, and show that the slope of the observed relation is in agreement with both the L-T relation based on numerical simulations and X-ray emission observations, and the M_gas-L relation based on observations. The slope of the Delta T_SZ-L relation is also consistent with the M_tot-L relation, where M_tot is the cluster total mass based on gravitational lensing observations. This agreement may be taken to imply a constant gas mass fraction within galaxy clusters, however, there are large uncertainties, dominated by observational errors, associated with these relations. Using the Delta T_SZ-L relation and the cluster X-ray luminosity function, we evaluate the local cluster contribution to arcminute scale cosmic microwave background anisotropies. The Compton distortion y-parameter produced by massive galaxy clusters through SZ effect is roughly two orders of magnitude lower than the current upper limit based on FIRAS observations.