Electromagnetic Energy Extraction from Kerr Black Holes: Ab-Initio Calculations

TL;DR

This paper uses ab-initio simulations to analyze electromagnetic energy extraction from Kerr black holes, confirming the Blandford-Znajek mechanism's robustness and providing accurate luminosity estimates across black hole masses.

Contribution

First ab-initio collisionless kinetic simulations of Kerr black-hole magnetospheres across various spins, validating the Blandford-Znajek mechanism with high accuracy.

Findings

Blandford-Znajek luminosity matches analytic predictions

Simulation results agree with general-relativistic magnetohydrodynamics

Electromagnetic luminosity estimates are robust across black hole spins

Abstract

The possibility of extracting energy from a rotating black hole via the Blandford-Znajek mechanism represents a cornerstone of relativistic astrophysics. We present general-relativistic collisionless kinetic simulations of Kerr black-hole magnetospheres covering a wide range in the black-hole spin. Considering a classical split-monopole magnetic field, we can reproduce with these ab-initio calculations the force-free electrodynamics of rotating black holes and measure the power of the jet launched as a function of the spin. The Blandford-Znajek luminosity we find is in very good agreement with analytic calculations and compatible with general-relativistic magnetohydrodynamics simulations via a simple rescaling. These results provide strong evidence of the robustness of the Blandford-Znajek mechanism and accurate estimates of the electromagnetic luminosity to be expected in those scenarios involving rotating black holes across the mass scale.