Accretion Disc

An accretion disc is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a central body. The central body is typically a star. Gravity causes material in the disc to spiral inward towards the central body. Gravitational forces compress the material causing the emission of electromagnetic radiation. The frequency range of that radiation depends on the central object. Accretion discs of young stars and protostars radiate in the infrared; those around neutron stars and black holes in the X-ray part of the spectrum.

Read more about Accretion DiscManifestations, Accretion Disc Physics, Analytic Models of Sub-Eddington Accretion Discs (thin Discs, ADAFs), Analytic Models of Super-Eddington Accretion Discs (slim Discs, Polish Doughnuts)

Other articles related to "accretion disc, discs, accretion discs, accretion, disc":

Polar Jet
... It is usually caused by the dynamic interactions within an accretion disc ... of bipolar nebulae) List of unsolved problems in physics Why do the discs surrounding certain objects, such as the centers of active galaxies, emit ... Accretion discs around many stellar objects are able to produce jets, although those around a black hole are the fastest and most active ...
Analytic Models of Super-Eddington Accretion Discs (slim Discs, Polish Doughnuts)
... The theory of highly super-Eddington black hole accretion, M>>MEdd, was developed in the 1980s by Abramowicz, Jaroszynski, Paczyński, Sikora and others in terms of "Polish doughnuts" (the name was coined by Rees) ... optically thick, radiation pressure supported accretion discs cooled by advection ... Slim discs (name coined by Kolakowska) have only moderately super-Eddington accretion rates, M≥MEdd, rather disc-like shapes, and almost thermal spectra ...
Cataclysmic Variable Star - Classification
... some cases the magnetic field of the white dwarf is strong enough to disrupt the inner accretion disk or even prevent disk formation altogether ... the white dwarf rather than forming a disc ... polars', these have a slightly weaker magnetic field than AM Herculis stars there is an accretion disc, but substructure in it is created by the field ...
SS 433 - System
... star which rapidly loses mass into an accretion disc formed around the central object ... The accretion disc is subject to extreme heating as it spirals into the primary and this heating causes the accretion disc to give off intense X-rays ...

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