  We report the detection of both soft and hard excess X-ray emission in the
cluster of galaxies A 2199, based upon spatially resolved spectroscopy with
data from the BeppoSAX, EUVE and ROSAT missions. The excess emission is visible
at radii larger than 300 kpc and increases in strength relative to the
isothermal component. The total 0.1-100 keV luminosity of this component is 15
% of the cluster luminosity, but it dominates the cluster luminosity at high
and low energies. We argue that the most plausible interpretation of the excess
emission is an inverse Compton interaction between the cosmic microwave
background and relativistic electrons in the cluster. The observed spatial
distribution of the non-thermal component implies that there is a large halo of
cosmic ray electrons between 0.5-1.5 Mpc surrounding the cluster core. The
prominent existence of this component has cosmological implications, as it is
significantly changing our picture of a clusters's particle acceleration
history, dynamics between the thermal and relativistic media, and total mass
budgets.
