Stacking weak-lensing signals of Sunyaev-Zel'dovich clusters to constrain cluster physics

We show how to place constraints on cluster physics by stacking the weak-lensing signals from multiple clusters found through the Sunyaev-Zel'dovich (SZ) effect. For a survey that covers about 200 deg(2) in both SZ and weak-lensing observations, the slope and amplitude of the mass versus SZ luminosity (L-SZ) scaling relation can be measured with few percent error for clusters at z similar to 0.5. This can be used to constrain cluster physics, such as the nature of feedback. For example, we can distinguish a preheated model from a model with a decreased accretion pressure at more than 5 sigma. The power to discriminate among different nongravitational processes in the intracluster medium becomes even stronger if we use the central Compton parameter, y(0), which could allow one to distinguish among models with preheating, supernova feedback, and active galactic nucleus feedback at more than 5 sigma. Furthermore, by measuring these relations as a function of redshift, it would be possible to directly observe, e. g., the evolution of hot gas in clusters. With this approach, the mass-L-SZ relation can be calibrated and its uncertainties can be quantified, leading to a more robust determination of cosmological parameters from cluster surveys. The mass-L-SZ relation calibrated in this way from a small area of the sky can be used to determine masses of SZ clusters from very large SZ-only surveys and is nicely complementary to other techniques proposed in the literature.