• DOI:10.1086/187381
• Corpus ID: 8998323

Advection-dominated Accretion: A Self-similar Solution

@article{Narayan1994AdvectiondominatedAA,
  title={Advection-dominated Accretion: A Self-similar Solution},
  author={Ramesh Narayan and In-su Yi},
  journal={The Astrophysical Journal},
  year={1994},
  volume={428}
}

• R. Narayan, I. Yi
• Published 1 March 1994
• Physics
• 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 cease to spin up long before they reach the break-up limit. Further, the Bernoulli parameter is positive, implying that advection-dominated flows are susceptible to producing outflows. Convection is likely in many of these flows and, if present, will tend to enhance the above effects. We suggest that advection-dominated accretion may provide an explanation for the slow spin rates of accreting stars and the widespread occurrence of outflows and jets in accreting systems.