On the ISW-cluster cross-correlation in future surveys

Abstract

We investigate the cosmological information contained in the cross-correlation between the integrated Sachs-Wolfe (ISW) of the cosmic microwave background (CMB) anisotropy pattern and galaxy clusters from future wide surveys. Future surveys will provide cluster catalogues with a number of objects comparable with galaxy catalogues currently used for the detection of the ISW signal by cross-correlation with the CMB anisotropy pattern. By computing the angular power spectra of clusters and the corresponding cross-correlation with CMB, we perform a signal-to-noise ratio (SNR) analysis for the ISW detection as expected from the eROSITA and the Euclid space missions. We discuss the dependence of the SNR of the ISW-cluster cross-correlation on the specifications of the catalogues and on the reference cosmology. We forecast that the SNRs for ISW-cluster cross-correlation are slightly smaller compared to those which can be obtained from future galaxy surveys but the signal is expected to be detected at high significance, i.e. more than > 3 σ. We also forecast the joint constraints on parameters of model extensions of the concordance Λ cold dark matter (ΛCDM) cosmology by combining CMB and the ISW-cluster cross-correlation.