2001ApJ...562L.163K

We report the first X-ray detection of the radio pulsar PSR B1757-24 using the Chandra X-Ray Observatory. We detect point-source emission at the pulsar position plus a faint tail extending nearly 20" east of the pulsar, in the same direction and with comparable morphology to the radio tail. Assuming the point-source X-ray emission is magnetospheric, the observed X-ray tail represents only ∼0.01% of the pulsar's spin-down luminosity. This is significantly lower than the analogous efficiencies of most known X-ray nebulae surrounding rotation-powered pulsars. Assuming a nonthermal spectrum for the tail photons, we show that the tail is unlikely to be emission left behind following the passage of the pulsar but rather is probably from synchrotron-emitting pulsar wind particles having a flow velocity of ∼7000 km.s^–1. We also show that there must be a significant break in the tail synchrotron spectrum between the radio and X-ray bands that is intrinsic to the particle spectrum. No emission is detected from the shell supernova remnant G5.4-1.2. The upper limits on remnant emission are unconstraining.