MAGNETOTHERMAL EVOLUTION OF NEUTRON-STARS

The field decay in neutron stars depends on the properties of matter i n the core region. Joule heating accompanying the field decay can sign ificantly influence the thermal history of neutron stars. The present paper deals with the magnetic and thermal evolutions of neutron star w ith the internal magnetic field. Two possible models of superdense mat ter are considered, one with neutrons in normal state and the other wi th neutron superfluidity. In both cases the internal field can decay o n rather short time scale of the order of similar to 1 - 50 Myr. Joule heating should essentially slow down neutron star cooling, particular ly, 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.