Cross-correlation between thermal Sunyaev-Zeldovich effect and the integrated Sachs-Wolfe effect

Abstract

Large-angle fluctuations in the cosmic microwave background temperature induced by the integrated Sachs-Wolfe effect and Compton-y distortions from the thermal Sunyaev-Zeldovich (tSZ) effect are both due to line-of-sight density perturbations. Here we calculate the cross-correlation between these two signals. Measurement of this cross-correlation can be used to test the redshift distribution of the tSZ distortion, which has implications for the redshift at which astrophysical processes in clusters begin to operate. We also evaluate the detectability of a yT cross-correlation from exotic early-Universe sources in the presence of this late-time effect.