Gas flows in from all sorts of directions, and if an accretion disk
forms at all, it will never grow very large due to encounters with nearby forming stars.
Matter falling toward a black hole collects into a rotating accretion disk
, where it becomes compressed and heated before eventually spilling over the black hole's event horizon, the point beyond which nothing can escape and astronomers cannot observe.
If an accretion disk
partially blocks the view, the intensity of any detected X-ray burst represents only a fraction of its true intensity.
The very high luminosity of quasars, enough to outshine their host galaxies, comes from the fact that they emit radiation across the entire electromagnetic spectrum, which is due to the energy released when gas from the accretion disk
around a supermassive black hole (quasars consist of a supermassive black hole and an accretion disk
) falls onto the black hole.
The more massive the black hole, the brighter its accretion disk
The X-rays are produced when a swirling accretion disk
of gas and dust that surrounds the black hole creates a multimillion-degree cloud, or corona near the black hole.
This may reflect a tilt of the accretion disk
surrounding the supermassive black hole.
In the early stage of the pair's evolution, according to Kluzniak and his associates, the pulsar -- a rapidly spinning, very dense neutron star -- is surrounded by an accretion disk
of matter that falls onto the surface of the pulsar and makes it spin faster.
As matter falls onto the supermassive black hole, it forms an accretion disk
which eventually grows too large for the black hole to "digest" efficiently.
This gas streamer probably originates near the accretion disk
, mere light-days from the central black hole, and flows outward at 1,000 kilometers per second (2 million mph).
The X-rays are believed to be radiation from a hot accretion disk
around the black hole.
In an unmagnetized binary system, matter falling onto the white dwarf forms an accretion disk
, a disk of matter slowly spiraling down.