Importance of Compton scattering for radiation spectra of isolated neutron stars

Abstract

Abstract. Model atmospheres of isolated neutron stars with low magnetic field are calculated with Compton scattering taking into account. Models with effective temperatures 1, 3 and 5 MK, with two values of surface gravity (log g = 13.9 and 14.3), and different chemical compositions are calculated. Radiation spectra computed with Compton scattering are softer than the computed with Thomson scattering at high energies (E> 5 keV) for hot (T eff > 1 MK) atmospheres with hydrogen-helium composition. Compton scattering is more significant to hydrogen models with low surface gravity. The emergent spectra of the hottest (T eff > 3 MK) model atmospheres can be described by diluted blackbody spectra with hardness factors ∼ 1.6 -1.9. Compton scattering is less important for models with solar abundance of heavy elements.