Effect of magnetic field inclination on black hole jet power and particle acceleration

TL;DR

This study uses 3D simulations to investigate how the inclination of magnetic fields around rotating black holes influences jet power and particle acceleration, revealing that while jet power decreases with inclination, particle acceleration remains efficient.

Contribution

First kinetic analysis of inclined magnetic fields around Kerr black holes showing reduced jet power but sustained particle acceleration.

Findings

Oblique magnetic fields significantly reduce jet power.

Particle acceleration remains highly efficient regardless of magnetic field inclination.

Black holes with weak jets can still be bright sources of nonthermal radiation.

Abstract

Rotating black holes are known to launch relativistic jets and accelerate particles provided they accrete a magnetized plasma. However, it remains unclear how the global magnetic field orientation affects the jet powering efficiency. Here, we propose the first kinetic study of a collisionless plasma around a Kerr black hole that is embedded in a magnetic field inclined with respect to the black hole's spin axis. Using three-dimensional general-relativistic particle-in-cell simulations, we show that while oblique magnetic field configurations significantly reduce the jet power, particle acceleration remains highly efficient regardless. This suggests that black holes producing a weak jet could still be bright sources of nonthermal radiation and cosmic rays.