Relativistic Jets are powerful jets of plasma which emerge from the centers of active galaxies. A jet is created from subatomic particles and magnetic fields in the accretion disk of the supermassive black hole in the nucleus of an active galaxy. The twisting of magnetic fields in the accretion disk collimates the flow along the rotation axis of the black hole, so when conditions are suitable, a jet will emerge from each face of the accretion disk.

Similar jets, though on a much smaller scale, can develop around the accretion disks of neutron stars and stellar black holes.