Exascale simulations of magnetized turbulence driven by supermassive black hole feedback in galaxy clusters*

Galaxy clusters are the most massive virialized objects in the universe, with masses hundreds to thousands of times that of our own Milky Way and physical scales extending for megaparsecs. The bulk of the baryons contained within these systems is comprised of a hot (10⁷-10⁸ K), diffuse (with particle number densities of n ~ 10^-6 - 10^-1 cm^-3), and magnetized plasma that glows brightly in X-ray wavelengths (with typical X-ray luminosities of 10⁴⁴-10⁴⁵ erg/s). The energy radiated away by X-rays is replaced by heating from active galactic nuclei, which are relativistic jets powered by accretion onto the supermassive black hole in the cluster's central galaxy, maintaining the system in a dynamic equilibrium. This heating occurs through interactions of the AGN jet with the intracluster medium, which ultimately is transported throughout the highly X-ray luminous cluster core. In this presentation I will present results from exascale magnetohydrodynamics simulations of idealized galaxy clusters with a cold gas accretion-fed, magnetized AGN jet in the center. I will explain the mechanisms by which cold gas triggers the AGN jet, and how the heating from this jet regulates the amount of cold gas in the system.  I will also discuss in detail the generation of turbulence by the magnetized jet, the amplification of the ambient cluster magnetic fields by turbulence-driven dynamos, and I will compare this to more idealized simulations of plasma turbulence.