1608.07581
Cross-correlating Planck tSZ with RCSLenS weak lensing: implications for cosmology and AGN feedback
Hojjati, et al
Present measurements of the spatial mapping between (hot) baryons and the total matter in the Universe, via the cross-correlation between the tSZ map from Planck and the WL maps from RCSLenS. The cross-correlations are performed on the map level where all the sources (including diffuse intergalactic gas) contribute to the signal. Consider two configuration-space correlation function estimators, xi^{y-kappa} and xi^{y-gamma_t}, and a Fourier space estimator, C^{y-kappa}_ell, in the analysis. Detect a significant correlation out to 3 degrees of angular separation on the sky. Based on statistical noise only, report 13 sigma and 17 sigma detections of the cross-correlation using the configuration-space y-kappa and y-gamma_t estimators, respectively. Including a heuristic estimate of the sampling variance yields a detection significance of 6 sigma and 8 sigma, respectively. A similar level of detection is obtained from the Fourier-space estimator, C^{y-kappa}_ell. As each estimator probes different dynamical ranges, their combination improves the significance of the deletion. Compare the measurements with predictions from the cosmos-OWLS suite of cosmo hydrodynamical sims, where different galactic feedback models are implemented. Find that a model with considerable AGN feedback that removes large quantities of hot gas from galaxy groups and WMAP-7yr best-fit cosmological parameters provides the best match to the measurements. All baryonic models in the context of a Planck cosmology over-predict the observed signal. Similar cosmo conclusions are drawn when a halo model with the observed 'universal' pressure profile is employed.
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