Model atmospheres of hot neutron star

We present model atmospheres for very hot neutron stars (X-ray burst sources). The model equations assume both hydrostatic and radiative equilibrium, and the equation of state of an ideal gas in local thermodynamic equilibrium (LTE). The equation of radiative transfer includes terms describing Compton scattering of photons on free electrons in fully relativistic thermal motion, for photon energies approaching m_ec^2. % An exact description of Compton scattering is very important for the accurate determination of basic % neutron star parameters in X-ray bursters. For this reason many authors have computed models of % neutron star atmospheres with various degrees of sophistication in the treatment of Compton % scattering. Model equations take into account many bound-free and free-free energy-dependent opacities of hydrogen, helium, and the iron ions, and also a dozen bound-bound opacities for the highest ions of iron. We calculated large grid of our models, which were used to fitting the observed spectra.