  Fast magnetic reconnection events can be a very powerful mechanism operating
at the jet launching region of microquasars and AGNs. We have recently found
that the power released by reconnection between the magnetic field lines of the
coronal inner disk region and the lines anchored into the black hole is able to
accelerate relativistic particles through a first-order Fermi process and
produce the observed radio luminosity from both microquasars and low luminous
AGNs (LLAGNs). We also found that the observed correlation between the radio
luminosity and the mass of these sources, spanning 10^9 orders of magnitude in
mass, is naturally explained by this process. In this work, assuming that the
gamma-ray emission is probably originated in the same acceleration zones that
produce the radio emission, we have applied the scenario above to investigate
the origin of the high energy outcomes from an extensive number of sources
including high (HLAGNs) and LLAGNs, microquasars and GRBs. We find correlation
of our model with the gamma emission only for microquasars and a few LLAGNs,
while none of the HLAGNs or GRBs are fitted, neither in radio nor in gamma. We
attribute the lack of correlation of the gamma emission for most of the LLAGNs
to the fact that this processed emission doesn't depend only on the local
magnetic field activity around the source/accretion disk, but also on other
environmental factors like the photon and density fields. We conclude that the
emission from the LLAGNs and microquasars comes from the nuclear region of
their sources and therefore, can be driven by nuclear magnetic activity.
However, in the case of the HLAGNs and GRBs, the nuclear emission is blocked by
the surrounding density and photon fields and therefore, we can only see the
jet emission further out.
