Cluster magnetic fields from active galactic nuclei

TL;DR

This paper uses 3D MHD simulations to investigate how active galactic nuclei can generate and distribute magnetic fields throughout galaxy clusters, focusing on jet feedback effects.

Contribution

It introduces adaptive mesh refinement MHD simulations with various sub-resolution models to study AGN-driven magnetization of galaxy clusters.

Findings

AGN jets can significantly magnetize the cluster medium.

Different accretion models affect the magnetic field distribution.

Magnetized outflows influence black hole growth and feedback.

Abstract

Active galactic nuclei (AGN) found at the centers of clusters of galaxies are a possible source for weak cluster-wide magnetic fields. To evaluate this scenario, we present 3D adaptive mesh refinement MHD simulations of a cool-core cluster that include injection of kinetic, thermal, and magnetic energy via an AGN-powered jet. Using the MHD solver in FLASH 2, we compare several sub-resolution approaches that link the estimated accretion rate as measured on the simulation mesh to the accretion rate onto the central black hole and the resulting feedback. We examine the effects of magnetized outflows on the accretion history of the black hole and discuss the ability of these models to magnetize the cluster medium.