Advection-dominated Accretion: A Self-similar Solution

  title={Advection-dominated Accretion: A Self-similar Solution},
  author={Ramesh Narayan and In-su Yi},
  journal={The Astrophysical Journal},
We consider viscous rotating accretion flows in which most of the viscously dissipated energy is stored as entropy rather than being radiated. Such advection-dominated flows may occur when the optical depth is either very small or very large. We obtain a family of self-similar solutions where the temperature of the accreting gas is nearly virial and the flow is quasi-spherical. The gas rotates at much less than the Keplerian angular velocity; therefore, the central stars in such flows will… 
Self-similar Solution of Optically Thick Advection-dominated Flows
The photons released by the viscosity process in a disk with accretion rate exceeding the Eddington critical value will be trapped and restored as entropy in the accreting gas rather than being
Global dynamics of radiatively inefficient accretion flows: advection versus convection
We obtain global solutions for radiatively inefficiently accretion flows around black holes. Whether and where convection develops in a flow are self-consistently determined by mixinglength theory.
The role of thermal conduction in magnetized viscous–resistive advection‐dominated accretion flows
Observations of the hot gas that surrounds Sgr A * and a few other nearby galactic nuclei imply that the mean free paths of electrons and protons are comparable to the gas capture radius. Hot
Time-dependent quasi-spherical accretion
ABSTRA C T Differentially rotating, ‘advection-dominated’ accretion flows are considered in which the heat generated by viscous dissipation is retained in the fluid. The equations of time-dependent
Dynamics of the Transition from a Thin Accretion Disk to an Advection-dominated Accretion Flow
We consider an optically thin advection-dominated accretion flow (ADAF) that is connected at a finite transition radius to an outer optically thick, geometrically thin disk. We include turbulent
Preheated Advection-dominated Accretion Flow
The advection-dominated accretion flow (ADAF) has been quite successful in explaining a wide variety of accretion-powered astronomical sources. The physical characteristics of ADAF complement the
Compton-heated Outflow from Convection-dominated Accretion Flows
Convection-dominated accretion flows (CDAFs) are expected to have a shallower density profile and a higher radiation efficiency compared to advection-dominated accretion flows (ADAFs). Both solutions
Advection-Dominated Accretion with Infall and Outflows
We present self-similar solutions for advection-dominated accretion flows with radial viscous force in the presence of outflows from the accretion flow or infall. The axisymmetric flow is treated in
Advection-dominated Inflow/Outflows from Evaporating Accretion Disks.
This Letter investigates the properties of advection-dominated accretion flows (ADAFs) fed by the evaporation of a Shakura-Sunyaev accretion disk (SSD), and finds that, because of global angular momentum conservation, a significant fraction of the hot gas flows away from the black hole, forming a transsonic wind.
Influence of Ohmic Heating on Advection-dominated Accretion Flows
Advection-dominated, high-temperature, quasi-spherical accretion flow onto a compact object, recently considered by a number of authors, assumes that the dissipation of turbulent energy of the flow


Accretion power in astrophysics
1. Accretion as a source of energy 2. Gas dynamics 3. Plasma concepts 4. Accretions in binary systems 5.Accretion discs in active galactic nuclei 6. Accrete on to a compact object 7. Active galacticuclei 8. Thick discs 9. Acc diffusion 10. thick discs 11. accretion flows.