X-ray and ultraviolet radiation from accreting white dwarfs. IV - Two-temperature treatment with electron thermal conduction

The authors report the results of detailed numerical calculations of the shock structures and the X-ray and UV emission produced by spherical accretion onto nonmagnetic white dwarfs. These calculations improve on earlier work by allowing the temperatures of the electrons and the ions to differ and by including electron thermal conduction. These effects are important at high masses. It is found that they must be included in order to calculate accurate shock structures for white dwarfs more massive than 1 M_sun;, and accurate hard X-ray spectral temperatures and luminosities for white dwarfs more massive than 1.3 M_sun;. The results can be applied to magnetic white dwarfs as long as bremsstrahlung cooling of the emission region is more important than cyclotron cooling.