Black Hole Weather
Massimo Gaspari (INAF OAS)
Tuesday 17/11/2020 @ 14:00, Google Hangouts Meet
In this talk, I will focus on some of the key and recent results of our theoretical and observational campaign (BlackHoleWeather) which aims to unveil how supermassive black holes are coupled to the host multiphase halos, linking the inner gravitational radius to the cosmological scales and vice versa. Massively parallel hydrodynamical simulations show that the turbulent plasma (X-ray) halo radiatively cools via a top-down multiphase condensation rain of warm (optical/IR) filaments and molecular (radio) clouds. The multiphase precipitation inherits the hot halo kinematics and thermodynamics, thus establishing a “cosmic weather” and tight correlations with the SMBH mass. In the nuclear region, the recurrent collisions between the condensed clouds boost the SMBH accretion rate via Chaotic Cold Accretion (CCA). The rapid CCA variability triggers powerful AGN outflows that quench the macro-scale cooling flow via cavities, shocks and turbulence, hence preserving the host atmospheres in quasi thermal equilibrium through several billion years.