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Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE
Abstract:
We present a Chandra X-ray survey of the disrupted recycled pulsars (DRPs),
isolated radio pulsars with P > 20 ms and B_s < 3E10 G. These observations were
motivated as a search for the immediate descendants of the approx. 10 central
compact objects (CCOs) in supernova remnants, three of which have similar
timing and magnetic properties as the DRPs, but are bright, thermal X-ray
sources consistent with minimal neutron star cooling curves. Since none of the
DPRs were detected, there is no evidence that they are "orphaned" CCOs, neutron
stars whose supernova remnants has dissipated. Upper limits on their thermal
X-ray luminosities are in the range log Lx[erg/s] = 31.8-32.8, which implies
cooling ages > 1E4 - 1E5 yr, roughly 10 times the ages of the approximately 10
known CCOs in a similar volume of the Galaxy. The order of a hundred CCO
descendants that could be detected by this method are thus either intrinsically
radio quiet, or occupy a different region of (P,B_s) parameter space from the
DRPs. This motivates a new X-ray search for orphaned CCOs among radio pulsars
with larger B-fields, which could verify the theory that their fields are
buried by fall-back of supernova ejecta, but quickly regrow to join the normal
pulsar population.
