Hot accretion discs with advection

Hot accretion discs with thermal Comptonisation and advection in luminous black hole sources

We solve for the structure of a hot accretion disc with unsaturated thermal Comptonisation 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 < ∼ 0.15y 3/5 α 7/5 of the Eddington limit, where y and α are the Compton and viscosity parameters, respectively. The characteristic te...

Stability of a hot two-temperature accretion disc with advection

The effects of radial advection and thermal diffusion were considered in investigating the linear stability of an optically thin, two-temperature accretion disc. If the disc has only very little advection, we proved that the thermal instability exists when the disc is geometrically thin. But it dispears in a geometrically slim disc if the thermal diffusion was considered. Moreover, if the disc ...

Vertical Structure of Accretion Discs with Hot Coronae in AGN

We study vertical structure of radiation pressure dominated disc with a hot corona. We include all the relevant processes like bound–free opacity and convection. We show that the presence of the corona modifies considerably the density and the opacity of the disc surface layers which are important from the point of view of spectrum formation. The surface of the disc with a corona is much denser...

A Simplified Solution for Advection Dominated Accretion Flows with Outflow

The existence of outflow in the advection dominated accretion flows has been confirmed by both numerical simulations and observations. The outow models for ADAF have been investigated by several groups with a simple self similar solution. But this solution is inaccurate at the inner regions and can not explain the emitted spectrum of the flow; so, it is necessary to obtain a global solution for...

Variability associated with a accretion disc theory for standard and advection-dominated discs