2111
20160701171658.0
10.1093/mnras/stv404
DOI
ASTROimport-268
van Hoof, P. A. M.
2015
Accurate determination of the free-free Gaunt factor - II. Relativistic Gaunt factors
When modelling an ionized plasma, all spectral synthesis codes need the thermally averaged free-free Gaunt factor defined over a very wide range of parameter space in order to produce an accurate prediction for the spectrum. Until now no data set exists that would meet these needs completely. We have therefore produced a table of relativistic Gaunt factors over a much wider range of parameter space than has ever been produced before. We present tables of the thermally averaged Gaunt factor covering the range 10log γ2 = -6 to 10 and 10log u = -16 to 13 for all atomic numbers Z = 1 through 36. The data were calculated using the relativistic Bethe-Heitler-Elwert (BHE) approximation and were subsequently merged with accurate non-relativistic results in those parts of the parameter space where the BHE approximation is not valid. These data will be incorporated in the next major release of the spectral synthesis code CLOUDY. We also produced tables of the frequency integrated Gaunt factor covering the parameter space 10log γ2 = -6 to +10 for all values of Z between 1 and 36. All the data presented in this paper are available online.
Ferland, G. J.
Williams, R. J. R.
Volk, K.
Chatzikos, M.
Lykins, M.
Porter, R. L.
Monthly Notices of the Royal Astronomical Society
449
2
2015
2112-2118
http://esoads.eso.org/abs/2015MNRAS.449.2112V
published in
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