Extragalactic jets are prominent astrophysical objects that are characterized by extended synchrotron emission. In situ acceleration in extragalactic jets cause the non-thermal radio up to x-ray radiation. Hadrons can, in principle, be accelerated up to the highest energies measured for ultrahigh energy cosmic rays. In particular, the Centaurus A jet seems to be a plausible source of the highest cosmic ray photons. Magnetic reconnection can locally convert magnetic energy to particle acceleration in field-aligned electric fields. These fields are associated with electric currents by a finite collisionless resistance.
Back-reaction instabilities of relativistic cosmic rays