Radio-quiet X-ray pulsars in Supernova Remnants and the ``Missing'' Pulsar Problem

摘要

The paradigm that young neutron stars (NSs) evolve as rapidly rotatingCrab-like pulsars requires re-examination. Evidence is accumulating that, infact, many young NS are slowly rotating (P ~ 10-s) X-ray pulsars, lacking indetectable radio emission. We present new results on three radio-quiet NScandidates associated with supernova remnants, which suggests that alternativeevolutionary-paths exist for young pulsars. These include the 12-s pulsator inKes 73, the 7-s pulsar near Kes 75, and the enigmatic X-ray source in RCW 103.We postulate that such objects account for the apparent paucity of radiopulsars in supernova remnants.