Bridging Scales in Black Hole Accretion and Feedback: Relativistic Jet linking the Horizon to the Host Galaxy

Simulating black hole (BH) accretion and feedback from the horizon to galactic scales is extremely challenging, as it involves a vast range of scales. For the first time, our multizone method has successfully achieved global dynamical steady-states of hot accretion flows in three-dimensional general relativistic magnetohydrodynamic (GRMHD) simulations by tracking the bidirectional interaction between a non-spinning BH and its host galaxy. In this talk, I present simulations of strongly magnetized Bondi accretion for various Bondi radii, RB ≈ 400, 2e3, 2e4, 2e5 rg, for both non-spinning (a=0) and spinning (a=0.9) BHs. We find that the BH accretion rate is suppressed with respect to the Bondi rate, depending on the Bondi radius RB. However, despite some variability, the time-averaged feedback efficiency is independent of RB, where the efficiency is η∼30% for a BH spin a=0.9. This suggests that BH feedback efficiency in hot accretion flows is mainly governed by the BH spin (a) rather than by the galactic properties (RB). From these first-principles simulations, we provide a feedback subgrid prescription for cosmological simulations and compare it with the BH models used in cosmological simulations.