1996A&A...312..186V

We present results of self-consistent numerical calculations of the reflected hard x-ray spectrum and the iron Kα fluorescence complex for irradiated white-dwarf atmospheres. The radiative transfer is calculated using an LTE atmosphere code which includes irradiation of the surface, absorption by metals, and redistribution by Compton scattering. We show that non-LTE effects are important in the surface inversion layer, but that they are not very important for the calculated iron Kα complex. The reflection albedo and the equivalent width and profile of the iron Kα complex depend on the inclination at which the irradiated atmosphere is observed. For low amounts of irradiation (< 10¹⁶ erg/s/cm2) we present values of the equivalent width and line center energy of the iron Kα complex and a simple analytic approximation for the reflection albedo. Both the equivalent width of the iron Kα complex and the reflection albedo are lower than formerly suggested. For higher amounts of irradiation a hot corona-like surface layer is formed and the fluorescence complex consists of a superposition of lines with different Comptonized profiles.