The self-regulated AGN feedback loop: the role of chaotic cold accretion

Understand

Supermassive black hole accretion and feedback play central role in the evolution of galaxies, groups, and clusters.

• I review how AGN feedback is tightly coupled with the formation of multiphase gas and the newly probed chaotic cold accretion (CCA).
• In a turbulent and heated atmosphere, cold clouds and kpc-scale filaments condense out of the plasma via thermal instability and rain toward the black hole.
• In the nucleus, the recurrent chaotic collisions between the cold clouds, filaments, and central torus promote angular momentum cancellation or mixing, boosting the accretion rate up to 100 times the Bondi rate.