Relativistic beaming (also known as
Doppler beaming, Doppler boosting, or the
headlight effect) is the process by which
relativistic effects modify the apparent luminosity of emitting matter that is moving at speeds close to the
speed of light. In an astronomical context, relativistic beaming commonly occurs in two oppositely-directed
relativistic jets of
plasma that originate from a central
compact object that is
accreting matter. Accreting compact objects and relativistic jets are invoked to explain the following observed phenomena:
x-ray binaries,
gamma-ray bursts, and, on a much larger scale,
active galactic nuclei (AGN). (
Quasars are also associated with an accreting compact object, but are thought to be merely a particular variety of
AGN.)