The Sunyaev-Zel'dovich effect and Faraday rotation contributions of galaxy groups to the CMB angular power spectrum

TL;DR

This paper investigates how galaxy groups and smaller halos contribute to the CMB's angular power spectrum through the Sunyaev-Zel'dovich effect and Faraday rotation, highlighting their importance in B-mode polarization.

Contribution

It provides a comprehensive analysis of the S-Z effect and Faraday rotation across a wide halo mass range, emphasizing the role of smaller halos in CMB polarization.

Findings

Smaller mass halos significantly influence B-mode polarization.

Faraday rotation dominates secondary B-modes at high multipoles.

Measurement of B-modes can constrain intracluster magnetic fields.

Abstract

The S-Z effect and Faraday rotation from halos are examined over a wide mass range, an including gas condensation and magnetic field evolution. Contributions to the CMB angular power spectrum are evaluated for galaxy clusters, galaxy groups and galaxies. Smaller mass halos are found to play a more important role than massive halos for the B-mode polarisation associated with the S-Z CMB anisotropies. The B-modes from Faraday rotation dominate the secondary B-modes caused by gravitational lensing at l > 3000. Measurement of B-mode polarisation in combination with the S-Z power spectrum can potentially provide important constraints on intracluster magnetic field and gas evolution at early epochs.