Open AccessHot accretion discs with thermal Comptonization and advection in luminous black hole sources
Author(s) -
Zdziarski Andrzej A.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01682.x
Subject(s) - physics , astrophysics , accretion (finance) , eddington luminosity , bremsstrahlung , radiative transfer , advection , photon , spectral line , thermal , black hole (networking) , active galactic nucleus , astronomy , galaxy , optics , computer network , routing protocol , routing (electronic design automation) , meteorology , computer science , thermodynamics , link state routing protocol
We solve for the structure of a hot accretion disc with unsaturated thermal Comptonization of soft photons and with advection, generalizing the classical model of Shapiro et al. The upper limit on the accretion rate due to advection constrains the luminosity to ≲ 0.15 y 3/5 α 7/5 of the Eddington limit, where y and α are the Compton and viscosity parameters, respectively. The characteristic electron temperature and Thomson optical depth of the inner flow at accretion rates within an order of magnitude of that upper limit are ∼ 10 9 K and ∼ 1, respectively. The resulting spectra are then in close agreement with the X‐ray and soft γ‐ray spectra from black hole binaries in the hard state and Seyferts. At low accretion rates, bremsstrahlung becomes the dominant radiative process.