On the role of fast magnetic reconnection in accreting black hole sources

TL;DR

This paper investigates how fast magnetic reconnection in magnetically-dominated accretion flows can explain radio and gamma-ray emissions in black hole systems, emphasizing core-region processes over jet-based models.

Contribution

It refines the MDAF model focusing on sub-Eddington accretion, establishing fast magnetic reconnection as a key mechanism in black hole core regions for certain sources.

Findings

Explains radio emission in microquasars and LLAGNs via magnetic reconnection.

Associates gamma-ray emission with core reconnection regions.

Finds blazars and GRBs emissions are not linked to core reconnection.

Abstract

We attempt to explain the observed radio and gamma-ray emission produced in the surrounds of black holes by employing a magnetically-dominated accretion flow (MDAF) model and fast magnetic reconnection triggered by turbulence. In earlier work, standard disk model was used and we refine the model by focussing on the sub-Eddington regime to address the fundamental plane of black hole activity. The results do not change substantially with regard to previous work ensuring that the details of the accretion physics are not relevant in the magnetic reconnection process occurring in the corona. Rather our work puts fast magnetic reconnection events as a powerful mechanism operating in the core region, near the jet base of black hole sources on more solid ground. For microquasars and low-luminosity active galactic nuclei (LLAGNs) the observed correlation between radio emission and mass of the sources can be explained by this process. The corresponding gamma-ray emission also seems to be produced in the same core region. On the other hand, the emission from blazars and gamma-ray bursts (GRBs) cannot be correlated to core emission based on fast reconnection.