Cooling neutron stars with localized protons
  We analyze cooling of neutron stars, assuming the presence of localized protons in the densest region of their cores. Choosing a single threshold density for proton localization and adjusting neutron star mass, we reproduce the observational data on effective surface temperatures of Vela and PSR 0656+14, with or without an accreted hydrogen envelope. However, the presence of a tiny hydrogen envelope is mandatory, in this model, for reproducing the Geminga data. 
D.A. Baiko (1) P. Haensel (2) ((1) Ioffe Physical Technical Institute,   St. Petersburg, Russia; (2) N. Copernicus Astronomi...