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

TL;DR

This paper calculates the cross-correlation between the thermal Sunyaev-Zeldovich effect and the integrated Sachs-Wolfe effect in the cosmic microwave background, providing a new way to probe cluster evolution and early-Universe phenomena.

Contribution

It introduces the first detailed calculation of the tSZ-ISW cross-correlation and assesses its potential to test cluster astrophysics and detect exotic early-Universe signals.

Findings

Cross-correlation can constrain the redshift distribution of tSZ distortions.

Measurement of the cross-correlation can test cluster formation epochs.

Potential to detect early-Universe signals in the presence of late-time effects.

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.