MAGNETOTHERMAL EVOLUTION OF NEUTRON-STARS

The field decay in neutron stars depends on the properties of matter in the core region. Joule heating accompanying the field decay can significantly influence the thermal history of neutron stars. The present paper deals with the magnetic and thermal evolutions of neutron star with the internal magnetic field. Two possible models of superdense matter are considered, one with neutrons in normal state and the other with neutron superfluidity. In both cases the internal field can decay on rather short time scale of the order of similar to 1 - 50 Myr. Joule heating should essentially slow down neutron star cooling, particularly, at the late evolutionary stage. In the case of superfluid neutrons an additional heating may be especially pronounced resulting even in an increase of the surface temperature at some stages.