Carbon and Oxygen Coronal Line Intensities for the Electron κ-DistributionI

Abstract

The ionization and excitation equilibrium of C and O for the electron κ-distribution in the solar corona is studied. The change of the distribution shape changes the ionization, recombination and excitation rates. These changes influence the relative ion abundance and the level populations. The ionization peaks are wider and the level populations are usually lower for this kind of non-thermal distribution. The diagnostics of the electron distribution shape from ionic composition and from the line intensities is shown. The synthetic spectrum in the region 500-2000 Å shows that some C iv, C iii and O iv lines are very sensitive to the shape of the electron distribution function. The enhancement of these lines by a factor 2-6 is observed for a strongly non-thermal distribution in comparison with the Maxwellian one. This result has been tested for DEMs in the CHIANTI database.