Relativistic jets are powerful, narrow streams of plasma that are ejected at speeds close to the speed of light from regions around black holes, neutron stars, or active galactic nuclei. These jets are highly energetic and can extend for thousands to even millions of light-years into space.
They form when matter falling into a compact object—like a supermassive black hole—creates an accretion disk. Magnetic fields in the disk can twist and channel some of this infalling matter away from the object’s poles, launching it outward at relativistic speeds.
Because the jets move so fast, they exhibit relativistic effects such as beaming (concentrating radiation in the direction of motion), time dilation, and Doppler shifting. These effects make jets appear much brighter if they are pointed toward Earth.
Relativistic jets are seen in systems like quasars, blazars, microquasars, and gamma-ray bursts, and they play a major role in galaxy evolution by transferring energy far from their source. Studying them provides insights into black hole physics, high-energy astrophysics, and the behavior of matter in extreme gravitational and magnetic fields.