Discovery of extended emission around the pulsar B0355+54
  PSR B0355+54 is one of the handful of pulsars that has been observed with both Chandra and XMM-Newton. The analysis of the archival data has revealed the pulsar and a ~30 arcsec compact nebula surrounding it. XMM-Newton also has detected a trail which extends ~6 arcmin and similar to the compact nebula is also counter-aligned with the proper motion of the pulsar. The spectrum of both the pulsar and the extended emission are well described by an absorbed power-law model. The measured flux corresponds to an efficiency of converting the spin-down luminosity into X-rays in the 2-10 keV band of ~0.01% and ~1% for the pulsar and the extended emission, respectively. From the XMM-Newton data we have detected pulsations at the expected radio period. The energetic and the extent of the extended emission can be explained by a Bow-shock formed by the motion of the pulsar through the interstellar medium. 
Tepedelenlioglu Emre and Ogelman Hakki