U2-2016
Supermassive black hole spin and jet evolution in hydrodynamic simulations
Supermassive black hole (SMBH) spin is a key but poorly constrained ingredient of the AGN feeding-feedback loop. Chaotic accretion of cold gas clouds delivers rapidly varying three-dimensional torques that drive spin evolution and jet-axis reorientation, and in turn spin regulates jet power. We introduce a time-dependent SMBH spin framework, linking resolved multiphase feeding at large and meso scales to unresolved angular-momentum transfer at the innermost stable circular orbit (ISCO). We perform GPU-accelerated hydrodynamical simulations of a radiatively cooling group atmosphere (100-kpc box) with jet feedback and SMBH spin evolution, resolving multiphase inflow and angular-momentum direction below parsec scales. We first compare different spin prescriptions to controlled, no-turbulence environments to select a physically meaningful model, which we then apply to low- and high-turbulence group setups. As presented in a couple of recent works, in these turbulent weathers it is important to track in particular the coherence of the delivered angular momentum, which regulates spin variability: the low-turbulence run preserves longer, connected feeding events and stronger secular spin evolution, whereas stronger turbulence fragments the inflow and enhances torque cancellation. I will conclude with an outlook on the current development of our simulations.
Host: Davide Gerosa