  We calculate the distribution of electrons in clusters of galaxies, resulting
from thermalization processes in the presence of stochastic acceleration due to
plasma waves. We show that the electron distribution can deviate from a
Maxwell-Boltzmann distribution, due to the effect of the stochastic energy
gain, provided waves can be sustained against damping. The non-thermal tail of
electrons can generate as bremsstrahlung emission a flux of hard X-rays
compatible with the ones recently detected in some clusters of galaxies.

Astrophysics