Relativistic e(+/-) particles and cosmic rays are accelerated in the magnet
ospheres of supermassive black holes and neutron stars. The possibility of
synchrotron radiation with extremely high intensity inside the deepest regi
ons of magnetospheres is investigated. Very high brightness temperatures ar
e expected for such radiation by relativistic protons, which can be made ev
en higher in the presence of non-stationary conditions, Doppler boosting an
d coherent processes. The main parameters for models of such high-brightnes
s-temperature radiation are determined. Two types of active galactic nuclei
(AGNs) are expected. One type is associated with the acceleration and ejec
tion of relativistic e(+/-) particles only (probably non-IDV sources and FR
-I radio galaxies). The second type of AGN is also associated with e(+/-) a
cceleration, but is dominated by the contribution of relativistic protons (
probably IDV sources and FR-II radio galaxies). Analogous objects for pulsa
rs are plerion and shell supernova remnants with neutron stars or pulsars w
ithout synchrotron nebulae, respectively.