Simulations of the Sunyaev-Zel'dovich Power Spectrum with AGN Feedback

TL;DR

This study uses hydrodynamical simulations to analyze how AGN feedback influences the Sunyaev-Zel'dovich power spectrum, improving agreement with observations and constraining intracluster gas models.

Contribution

It introduces a new AGN feedback model in simulations that better matches observed cluster properties and refines the understanding of SZ power spectrum uncertainties.

Findings

AGN feedback simulations align better with X-ray cluster data.

SZ power spectrum at high multipoles is sensitive to feedback models.

Inclusion of AGN feedback reduces tension in cosmological parameter estimates.

Abstract

We explore how radiative cooling, supernova feedback, cosmic rays and a new model of the energetic feedback from active galactic nuclei (AGN) affect the thermal and kinetic Sunyaev-Zel'dovich (SZ) power spectra. To do this, we use a suite of hydrodynamical TreePM-SPH simulations of the cosmic web in large periodic boxes and tailored higher resolution simulations of individual galaxy clusters. Our AGN feedback simulations match the recent universal pressure profile and cluster mass scaling relations of the REXCESS X-ray cluster sample better than previous analytical or numerical approaches. For multipoles $\ell\lesssim 2000$, our power spectra with and without enhanced feedback are similar, suggesting theoretical uncertainties over that range are relatively small, although current analytic and semi-analytic approaches overestimate this SZ power. We find the power at high 2000-10000 multipoles which ACT and SPT probe is sensitive to the feedback prescription, hence can constrain the theory of intracluster gas, in particular for the highly uncertain redshifts $>0.8$. The apparent tension between $\sigma_8$ from primary cosmic microwave background power and from analytic SZ spectra inferred using ACT and SPT data is lessened with our AGN feedback spectra.