On the influence of high energy electron populations on metal abundance estimates in galaxy groups and clusters

Abstract

Spectral line emissivities have usually been calculated for a Maxwellian electron distribution. But many theoretical works on galaxy groups and clusters and on the solar corona suggest to consider modified Maxwellian electron distribution functions to fit observed X-ray spectra. Here we examine the influence of high energy electron populations on measurements of metal abundances. A generalized approach which was proposed in the paper by Prokhorov et al. (2009) is used to calculate the line emissivities for a modified Maxwellian distribution. We study metal abundances in galaxy groups and clusters where hard X-ray excess emission was observed. We found that for modified Maxwellian distributions the argon abundance decreases for the HCG 62 group, the iron abundance decreases for the Centaurus cluster and the oxygen abundance decreases for the solar corona with respect to the case of a Maxwellian distribution. Therefore, metal abundance measurements are a promising tool to test the presence of high energy electron populations.Comment: 6 pages, 4 figures, accepted for publication in A&