Heat blanketing envelopes of neutron stars

Near the surface of any neutron star there is a thin heat blanketing envelope that produces substantial thermal insulation of warm neutron star interiors and that relates the internal temperature of the star to its effective surface temperature. Physical processes in the blanketing envelopes are reasonably clear but the chemical composition is not. The latter circumstance complicates inferring physical parameters of matter in the stellar interiors from observations of the thermal surface radiation of the stars and urges one to elaborate the models of blanketing envelopes. We outline physical properties of these envelopes, particularly, the equation of state, thermal conduction, ion diffusion and others. Various models of heat blankets are reviewed, such as composed of separate layers of different elements, or containing diffusive binary ion mixtures in or out of diffusion equilibrium. The effects of strong magnetic fields in the envelopes are outlined as well as the effects of high temperatures which induce strong neutrino emission in the envelopes themselves. Finally, we discuss how the properties of the heat blankets affect thermal evolution of neutron stars and the ability to infer important information on internal structure of neutron stars from observations. (c) 2021 Elsevier B.V. All right reserved

Automated summary

This passage discusses the impact of a heat blanketing envelope near the surface of neutron stars on their internal structure, as well as the challenges of determining physical parameters and detailing models. The physical properties of the envelopes, including equation of state, thermal conduction, and ion diffusion, are outlined. The effects of magnetic fields and high temperatures on the envelopes are discussed, along with the ability to infer important information about the internal structure of neutron stars from observations.