Supernova Fallback and Neutron Star Evolution

Abstract

We have calculated the evolution of neutron stars surrounded by asupernova fallback disk, with an improved estimate of the torqueexerted by the disk and the time dependence of the mass transfer rate.We show that, for reasonable distributions of its free parameters,the disk model is unable to produce any anomalous X-ray pulsars asobserved-the influence of the fallback disk on neutron star evolution wasoverestimated. Based on the calculated results, we also critically comment onthe fossil disk model proposed recently for young radio pulsars.