  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.
