A Multi-wavelength study of the Pulsar PSR B1929+10 and its X-ray trail
  We report on the emission properties of PSR B1929+10 and its putative X-ray trail from a multi-wavelength study performed with XMM-Newton, the ESO NTT, the HST, the Effelsberg 100m Radio Telescope and the Jodrell Bank Radio Observatory. The XMM-Newton observations confirm the existence of the diffuse emission with a trail morphology lying in a direction opposite to the transverse motion of the pulsar. The trail has a length of ~15 arcmin. Its spectrum is non-thermal and produced by electron-synchrotron emission in the shock between the pulsar wind and the surrounding medium. Assuming that the electron lifetime against synchrotron cooling is comparable to the source transit time over the X-ray trail length, the magnetic field strength in the trail emitting region is inferred to be ~5 uG. Inspecting data from the Effelsberg 11cm radio continuum survey of the Galactic plane we discovered an elongated feature apparently coincident with the X-ray trail. The emission properties observed from PSR 1929+10 are found to finally challenge the picture of the emission properties of old non-recycled rotation powered pulsars. Both, the temporal and spectral X-ray emission properties of PSR 1929+10 are in excellent agreement with a non-thermal and, thus, magnetospheric radiation dominated emission scenario. A flux contribution from the thermal emission of heated polar caps of ~7% is inferred from a best fitting composite Planckian and power law spectral model. The X-ray pulse profile is found to be markedly different from the broad sinusoidal pulse profile seen in the low statistic ROSAT data. Simulations in the framework of an outer-gap emission model are able to reproduce the observed X-ray pulse profile and its phase relation relative to the radio pulse. 
Werner Becker, Michael Kramer, Axel Jessner, Ronald E. Taam, Jian J.   Jia, Kwong S. Cheng, Roberto Mignani, Alberto Pellizz...