accretion disk
(disk around an astronomical body of material that is accreting)
An accretion disk is material around a star or other
massive astronomical body distributed in the shape of a disk
centered on the body, spiraling in toward the body, attracted by
gravity. Accretion disks are associated with interacting
binary stars, with protostars (protoplanetary disks
often include accretion) and with
black holes (black hole accretion disk or BHAD), including
supermassive black holes.
Disks form because material drawn toward a body by gravity generally
began with some motion sideways to the body, and thus doesn't
fall straight into it. Material consisting of interacting objects,
such as a gas, tend to form general patterns of movement, and swirl
around the body together; pressure arresting immediate accretion
and its own gravity drawing it into a flat, rotating disk, orbiting
the body. Accretion occurs, but slowly, as the material accreting at
the inner edge leaves a pressure deficit, drawing further disk
material toward the body. Once such a disk forms, any additional
material arriving from elsewhere is often drawn into the disk
pattern, replenishing it.
Characteristics such as the accreting body's temperature and
electromagnetic radiation affect the form of the disk, and models such as
the alpha disk model and advection dominated accretion flow (ADAF) model have been developed
to describe different scenarios.
(gravity,black holes,stars,binary stars,accretion,object type,disk type)
Further reading:
https://en.wikipedia.org/wiki/Accretion_disk
https://dictionary.obspm.fr/index.php?formSearchTextfield=accretion+disk&showAll=1
http://www.ifa.hawaii.edu/users/jpw/classes/star_formation/lectures/accretion_disks.pdf
http://www.scholarpedia.org/article/Accretion_discs
https://arxiv.org/abs/2201.07262
https://wwwmpa.mpa-garching.mpg.de/~henk/pub/disksn.pdf
Referenced by pages:
accretion
active galactic nucleus (AGN)
advection dominated accretion flow (ADAF)
AGN corona
alpha disk
Balmer jump (BJ)
black hole model
Blandford-Payne mechanism (BP process)
Blandford-Znajek mechanism (BZ process)
broad line region (BLR)
Cloudy
Compton scattering
decretion disk
disk
dwarf nova (DN)
dynamo
eclipse mapping
epicyclic frequency
final parsec problem
fluorescence
gravitationally bound
Institute of Theoretical Astrophysics (ITA)
jet
Lyman break (LB)
magnetic tower
magnetically arrested disk (MAD)
magnetorotational instability (MRI)
magnetospheric truncation radius
maser
microquasar
narrow line region (NLR)
pre-main-sequence star (PMS)
pulsar (PSR)
quasi-periodic oscillation (QPO)
retrograde accretion
Rossby wave instability (RWI)
shearing box
SMBH formation
spectral line
spiral density wave
SS 433
surface density (Σ)
thin disk
Thorne-Żytkow object (TZO)
tomography
Toomre Q parameter (Q)
vortex
Index