Collisionless accretion onto black holes: dynamics and flares

Understand

We study the accretion of collisionless plasma onto a rotating black hole from first principles using axisymmetric general-relativistic particle-in-cell simulations.

• We carry out a side-by-side comparison of these results to analogous general-relativistic magnetohydrodynamic simulations.
• Although there are many similarities in the overall flow dynamics, three key differences between the kinetic and fluid simulations are identified.
• Magnetic reconnection is more efficient, and rapidly accelerates a nonthermal particle population, in our kinetic approach.