The standard model of these objects is the Shakura–Sunyaev model. For 10 points each:
[10e] Name these circular regions of material that often form around compact objects like black holes.
ANSWER: accretion disks [prompt on disks]
[10m] The Shakura–Sunyaev model is a model of thin disks efficient at this process, in contrast to ADAF (“A-D-A-F”) disks. The pressure of this phenomenon equals a body’s self-gravity at the Eddington limit.
ANSWER: radiation [or word forms like radiate; accept radiation pressure; accept photon emission; accept answers specifying (the production of) photons or light or electromagnetic waves]
[10h] The Shakura–Sunyaev model also makes this common radiative assumption typically known by a three-letter acronym. Under this simplifying assumption, the source function of the radiative transfer equations depends only on temperature.
ANSWER: local thermodynamic equilibrium [or LTE; prompt on partial answers]
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