Relativistic jet
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Relativistic jets are powerful jets of plasma which emerge from the centers of active galaxies and quasars. 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 outflow along the rotation axis of the black hole, so when conditions are suitable, a jet will emerge from each face of the accretion disk. If the jet is oriented along the line of sight to earth, relativistic beaming will change its apparent brightness.
Similar jets, though on a much smaller scale, can develop around the accretion disks of neutron stars and stellar black holes.
Although a disk's magnetic field and rotation are believed responsible for the formation of the axial radiation jet, the observed jets are more tightly collimated than predicted by current theory.