Particle acceleration via magnetic reconnection near spinning black holes coupled to a surrounding disk

Accretion and ejection have been found to be tightly linked around stellar-mass and supermassive black holes (BHs). Since the seminal work by Blandford & Znajek in the 70’s, most models of rotating BH magnetospheres focused on a specific configuration where magnetic field lines passing through the BH are open, a particularly convenient framework to launch jets and outflows. In contrast, fewer studies considered the alternative case: a Kerr BH surrounded by a disk threaded by a large scale magnetic field connected to the BH.

In this talk, I will report on recent results we obtained by performing global particle-in-cell simulations in Kerr metric to capture the dynamics of the electromagnetic fields and of the pair plasma in the corona. We find that a hybrid magnetic topology develops with magnetic loops connecting the disk to the event horizon, open field lines threading the horizon and funneling a jet, and open magnetic field lines anchored in the disk. A Y-point seeds a current sheet where magnetic reconnection heats the corona and accelerates particles up to relativistic speeds, which provides a non-thermal source of hard X-rays above the disk. I will present synthetic synchrotron images and spectra, along with particle energy distribution.