Extracting energy from plunging region of a Kerr-Taub-NUT black hole by magnetic reconnection

TL;DR

This paper investigates how magnetic reconnection in the plunging region of a Kerr-Taub-NUT black hole affects energy extraction, revealing that gravitomagnetic charge suppresses efficiency and that the mechanism can explain observed jet power and radiative efficiency of GRS 1915+105.

Contribution

It introduces magnetic reconnection as a mechanism for energy extraction in Kerr-Taub-NUT black holes and shows its potential to explain observed jet power and radiative efficiency.

Findings

Gravitomagnetic charge suppresses energy extraction efficiency.

Magnetic reconnection can explain jet power and radiative efficiency of GRS 1915+105.

The parameter region for jet power overlaps with that for radiative efficiency.

Abstract

We have studied the energy extraction from a Kerr-Taub-NUT black hole via magnetic reconnection occurring in the plunging region. Our results show that the gravitomagnetic charge suppresses the energy extraction process through magnetic reconnection and reduces the corresponding extraction efficiency, which is opposite to the effects of the black hole spin and the magnetization parameter. Finally, we treat the energy extraction process through magnetic reconnection as a mechanism to revisit the problem of the observed jet power and radiative efficiency of GRS 1915+105. Our results show that the allowed black hole parameter region originating from the jet power has an intersection with the region from the radiative efficiency. This means that with this mechanism related to magnetic reconnection the Kerr-Taub-NUT metric can simultaneously explain the observed jet power and radiative efficiency for GRS 1915+105, which is not explained by other mechanisms in previous studies.