The remarkable jet of the quasar 4C+19.44
(PHYSorg.com Space & Earth)

Quasars are galaxies with massive black holes at their cores. So much energy is being radiated from near the nucleus of a quasar that it is much brighter than the rest of the entire galaxy. Much of that radiation is at radio wavelengths, produced by electrons ejected from the core at speeds very close to that of light, often in narrow, bipolar jets that are hundreds of thousands of light-years long. The fast-moving charged particles can also scatter photons of light, kicking them up in energy into the X-ray range. Even after more than two decades of study, however, there is still no clear conclusion as to the physical mechanism actually responsible for the X-ray emission. In more powerful quasars, it does appear that this scattering process dominates. In lower power jets, however, the emission characteristics suggest that the X-ray emission is dominated by magnetic field effects, not scattering.