Synchrotron versus compton interpretations for extended X-ray jets

A widely discussed explanation for the origin of the X-ray emission observed from knots in extended quasar jets with the Chandra X-Ray Observatory is Compton-scattered cosmic microwave background radiation by electrons with Lorentz factors gamma' similar to 10(2). This model faces difficulties in terms of total energy requirements and in explaining the spatial profiles of the radio, optical, and X-ray knots in sources such as PKS 0637-752, 3C 273, or PKS 1127-145. These difficulties can be resolved in the framework of one- and two-component synchrotron models. We propose a model in which the broadband radio-to-X-ray synchrotron emission in quasar jets is powered by collimated beams of ultrahigh energy neutrons and gamma-rays formed in the subparsec-scale jets. The decay of the neutral beam in the intergalactic medium drives relativistic shocks to accelerate nonthermal electrons of the ambient medium. A second synchrotron component arises from the injection of leptons with Lorentz factors >> 10(7) that appear in the extended jet in the process of decay of ultrahigh energy gamma-rays. This approach could account for qualitative differences in the extended X-ray jets of Fanaroff-Riley (FR) 1 and 2 galaxies. Detection of high-energy neutrinos from blazars and core-dominated quasars will provide strong evidence for this model.