Vacuum breakdown in a misaligned magnetized Kerr spacetime

TL;DR

This paper investigates vacuum breakdown and electron-positron pair creation around a Kerr black hole in an inclined magnetic field, revealing how the dyadoregion's structure and energy depend on inclination and magnetic alignment.

Contribution

It introduces a detailed analysis of the dyadoregion in misaligned magnetic fields around Kerr black holes, including energy estimates and plasma properties, advancing understanding of high-energy astrophysical phenomena.

Findings

Dyadoregion consists of multiple lobes with size and orientation depending on inclination.

Misaligned magnetic fields enhance pair creation compared to aligned fields.

Estimated electromagnetic energy and beaming factors relate intrinsic energy to observations.

Abstract

Electron-positron ($e^{+}e^{-}$) pair creation by vacuum breakdown around compact objects is believed to power high-energy astrophysical transients like gamma-ray bursts (GRBs). In this work, we focus on vacuum breakdown around a Kerr black hole (BH) immersed in an asymptotically uniform magnetic field that is inclined with respect to the BH spin axis. The dyadoregion, the region where the induced electric field exceeds the critical value $E_{\text{c}}=m_{e}^{2}c^{3}/(e\hbar)$, is identified via the electromagnetic invariants. It is found that the dyadoregion consists of several lobes whose number, size, and orientation vary with the inclination. We also estimate the electromagnetic energy available for pair creation and derive a beaming factor that allows a conversion between the intrinsic dyadoregion energy and the observed isotropic energy. The thermodynamic properties of the resulting electron-positron-photon ($e^{+}e^{-}\gamma$) plasma are included, revealing an initial magnetic dominance. The evaluation of the minimum magnetic field required shows that misaligned magnetic fields generally favor pair creation more than aligned ones.