We suggest a simple fitting formula to represent Comptonized X- and \gamma -ray spectra from a hot ( kT _ { e } \gtrsim 10 keV ) , Thomson thick ( \tau _ { T } \gtrsim 5 ) hybrid thermal/nonthermal plasma in spherical geometry with homogeneous soft-photon injection throughout the Comptonizing region .
We have used this formula to fit a large data base of Monte-Carlo generated photon spectra , and provide correlations between the physical parameters of the plasma and the fit parameters of our analytic fit function .
These allow us to construct Thomson thick Comptonization spectra without performing computer intensive Monte Carlo simulations of the high- \tau _ { T } hybrid-plasma Comptonization problem .
Our formulae can easily be used in data analysis packages such as XSPEC , thus rendering rapid \chi ^ { 2 } fitting of such spectra to real data feasible .