Cosmic Microwave and Infrared Backgrounds cross-correlation for ISW detection

TL;DR

This paper explores the cross-correlation between cosmic infrared and microwave backgrounds to detect the integrated Sachs-Wolfe effect, providing theoretical predictions and assessing detectability with current and future instruments.

Contribution

It models the CIB anisotropies with a linear bias spectrum and derives the CMB-CIB cross-correlation power spectrum for various instruments and frequencies.

Findings

Ideal case detection significance: 6-7 sigma.

Realistic case detection significance: 2-5 sigma.

Detection depends strongly on noise and astrophysical contaminants.

Abstract

We investigate the cross-correlation between the cosmic infrared and microwave backgrounds (CIB & CMB) anisotropies through the integrated Sachs-Wolfe effect. We first describe the CIB anisotropies using a linearly biased power spectrum, then derive the theoretical angular power spectrum of the CMB-CIB cross-correlation for different instruments and frequencies. We discuss the detectability of the ISW signal by performing a signal-to-noise (SNR) analysis with our predicted spectra. The significances obtained range from 6{\sigma} to 7{\sigma} in an ideal case, depending on the frequency ; in realistic cases which account for the presence of noise including astrophysical contaminants, the results span the range 2-5{\sigma}, depending strongly on the major contribution to the noise term.