  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.
