About the thermal state of optically thin plasmas under the influence of any photon spectra

The author mainly treats the thermal properties of cloud gas and intercloud gas of the Broad Line Region, in particular the physics of the hot intercloud plasma, considering the photon spectra up to gamma-energies taking into account the latest observations. In chapter 2 the physical processes in an atomic gas mixture of the 10 most frequent solar elements (H, He, C, N, O, Ne, Mg, Si, S, and Fe) in the temperature range of 102 K up to several 109 K are discussed, which lead to ionization and recombination under the influence of photons with energies between 10-9 eV and 1011 eV. The corresponding heating and cooling mechanisms and the spectral energy distribution of the emission of optically thin plasmas are dealt with. In chapter 3 the mathematical methods applied are introduced; the results of some test and model calculations are presented in chapter 4 together with some examples of their application. (orig./AH)