Constraints on AGN feedback from its Sunyaev-Zel'dovich imprint on the cosmic background radiation

TL;DR

This study constrains the thermal Sunyaev-Zel'dovich effect from AGN feedback on the cosmic microwave background by combining microwave and sub-mm data, finding no conclusive evidence for a significant SZ imprint.

Contribution

It introduces a method to break degeneracies in SZ measurements using combined microwave and sub-mm data, and provides new constraints on AGN feedback effects.

Findings

Detected SZ effect in galaxy clusters with high significance

Found a low-significance hint of SZ signal from QSOs

Results suggest lower thermal energy from AGN feedback than previous reports

Abstract

We derive constraints on feedback by active galactic nuclei (AGN) by setting limits on their thermal Sunyaev-Zel'dovich (SZ) imprint on the cosmic microwave background (CMB). The amplitude of any SZ signature is small and degenerate with the poorly known sub-mm spectral energy distribution of the AGN host galaxy and other unresolved dusty sources along the line of sight. Here we break this degeneracy by combining microwave and sub-mm data from Planck with all-sky far-infrared maps from the AKARI satellite. We first test our measurement pipeline using the Sloan Digital Sky Survey (SDSS) redMaPPer catalogue of galaxy clusters, finding a highly significant detection ($>$$20\sigma$) of the SZ effect together with correlated dust emission. We then constrain the SZ signal associated with spectroscopically confirmed quasi-stellar objects (QSOs) from SDSS data release 7 (DR7) and the Baryon Oscillation Spectroscopic Survey (BOSS) DR12. We obtain a low-significance ($1.6\sigma$) hint of an SZ signal, pointing towards a mean thermal energy of $\simeq 5 \times 10^{60}$ erg, lower than reported in some previous studies. A comparison of our results with high-resolution hydrodynamical simulations including AGN feedback suggests QSO host masses of $M_{200c} \sim 4 \times 10^{12}~h^{-1}M_\odot$, but with a large uncertainty. Our analysis provides no conclusive evidence for an SZ signal specifically associated with AGN feedback.