The role of fast magnetic reconnection on the radio and gamma-ray emission from the nuclear regions of microquasars and low luminosity AGNs

TL;DR

This study investigates how fast magnetic reconnection in the core regions of microquasars and low luminosity AGNs can explain their radio and gamma-ray emissions, comparing different reconnection mechanisms and expanding the source sample.

Contribution

It compares two fast magnetic reconnection mechanisms and demonstrates that turbulence-driven reconnection better explains observed emissions across a larger sample, including blazars and GRBs.

Findings

Turbulence-driven reconnection reproduces observed radio and gamma-ray emissions more accurately.

LLAGNs and microquasars follow a correlation between magnetic reconnection power and emission.

Blazars and GRBs likely have emission origins further out along their jets.

Abstract

Fast magnetic reconnection events can be a very powerful mechanism operating in the core region of microquasars and AGNs. In earlier work, it has been suggested that the power released by fast reconnection events between the magnetic field lines lifting from the inner accretion disk region and the lines anchored into the central black hole could accelerate relativistic particles and produce the observed radio emission from microquasars and low luminosity AGNs (LLAGNs). Moreover, it has been proposed that the observed correlation between the radio emission and the mass of these sources, spanning $10^{10}$ orders of magnitude in mass, might be related to this process. In the present work, we revisit this model comparing two different fast magnetic reconnection mechanisms, namely, fast reconnection driven by anomalous resistivity (AR) and by turbulence (as described in Lazarian and Vishiniac 1999). We apply the scenario above to a much larger sample of sources (including also blazars, and gamma-ray bursts - GRBs), and find that LLAGNs and microquasars do confirm the trend above. Furthermore, when driven by turbulence, not only their radio but also their gamma-ray emission can be due to magnetic power released by fast reconnection, which may accelerate particles to relativistic velocities in the core region of these sources. Thus the turbulent-driven fast reconnection model is able to reproduce better the observed emission than the AR model. On the other hand, the emission from blazars and GRBs does not follow the same trend as that of the LLAGNs and microquasars, suggesting that the radio and gamma-ray emission in these cases is produced further out along the jet, by another population of relativistic particles, as expected.