The old radio-quiet pulsar PSR J2055+2539 and its long comma bright X-ray trail

The Large Area Telescope on Fermi has opened up a new era in pulsar astronomy,detecting more than 120 gammaray pulsars, virgul30% of which are radio quiet. One ofthe most interesting pulsars discovered by the LAT is J2055+2539, radioquiet,with largest characteristic age (1.2E6 years) and one of the smallest spindownluminosities (Erot virgul5E33 erg/s). Its large gammaray flux implies a very smalldistance, consistent with its location off the plane. A previous short XMMobservation identified the Xray counterpart and revealed an unusually large andnarrow (11.x1.) extended feature, protruding from the pulsar. We propose a deepXMM observation to better characterize the spectrum of the pulsar, search forXray pulsations, and further investigate the nature of the extended feature. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]