  The interpretation of hard X-ray emission from galaxy clusters is still
ambiguous and different models proposed can be probed using various
observational methods. Here we explore a new method based on Fe line
observations.
  Spectral line emissivities have usually been calculated for a Maxwellian
electron distribution. In this paper a generalized approach to calculate the
iron line flux for a modified Maxwellian distribution is considered.
  We have calculated the flux ratio of iron lines for the various possible
populations of electrons that have been proposed to account for measurements of
hard X-ray excess emission from the clusters A2199 and Coma. We found that the
influence of the suprathermal electron population on the flux ratio is more
prominent in low temperature clusters (as Abell 2199) than in high temperature
clusters (as Coma).
