STEADY-STATE ENERGY-SOURCES IN NEUTRON-STARS

The thermal response of 1.4 M. neutron stars to steady state internal energy sources is studied. A thermal evolution model, which calculates the interior temperature distribution, is used. The potentially observable surface luminosity is lower than the source rate because of volume neutrino emission, nonisothermal temperature profiles, and redshift factors. Heating rates between 10(30) and 10(41) ergs s-1 are applied as either a central point source or an inner crust source. The latter models the heat generated as superfluid vortex lines break free from pinning nuclei. The latter case gives heat generation in the stellar layers between 10(12) and 10(14) g cm-3, peaking between 1.5 and 6 x 10(13) g cm-3. Results are given for a surface field B = 10(13) G and for B = 0. The effects of a central accelerated cooling mechanism, represented by a free-quark phase, are shown. These results from the thermal evolution model are compared with isothermal models to establish the range of validity of the latter.