  We investigate the spectrum of a quasi-monoenergetic ensemble of relativistic
electrons, especially for the mildly relativistic case, and discuss the effect
of inclination of the magnetic field on the emissivity. We apply the exact
theoretical description to the spectrum of the radio source Sgr A* which is
located at or very close to the dynamical center of our Galaxy. We find that
the radio-MIR spectrum can be reproduced well, but that the resulting
self-comptonized X-ray flux is much smaller than the observed one.
