Accretion disks, jets, and energy extraction from black holes

In many astronomical systems, the pull of gravity leads to the formation of accretion disks, which are often observed around compact objects, such as black holes. Furthermore, in many of these systems, relativistic, powerful  outflows in the form of jets are observed as well.  Due to its complexity, the exact nature of physical processes that take place in this accretion-compact object-jet system  is not fully clear.

Here, I introduce a novel, GPU-accelerated general-relativistic, radiative  magneto-hydrodynamic (GR-R-MHD) code which we developed in Bar Ilan in the past 7 years. This unique code is written in CUDA-c and uses OpenMP to parallelize multi-GPU setups, and allows high resolution simulations of accretion disks and the formation and structure of jets without the need of multi-node supercomputer infrastructure. I will show some of the recent results we obtained, including the effects of magnetic field, black hole spin and radiation field on the disk and jet structures and the emitted power. I will demonstrate that under the appropriate conditions, more energy can be extracted from the system than deposited, implying that it comes at the expense of the black hole rotational energy.