Stability analysis of the accretion line

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169007· OSTI ID:6480004

Soker, N ^[1]

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1. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (USA)

The stability of the flow along the accretion line in the Bondi-Hoyle-Lyttleton-type accretion flow is studied. The WKB approximation is used to analyze short wavelength linear perturbations of the axisymmetric steady state flow. The viscosity terms in the gasdynamical equations are included in the analysis. The radial modes are studied both in two- and three-dimensional accretion flow. Since a displaced accretion line cannot be defined in three-dimensional flow, the tangential modes are only analyzed in the two-dimensional flow. The analysis of the perturbed gasdynamical equations are made simpler as a result of the radial and tangential modes being decoupled in the linear regime. As was shown before, the three-dimensional accretion flow is unstable against radial modes. The two-dimensional accretion flow is found to be unstable against tangential modes, as well as against radial modes. Using typical numerical parameters which are in common use, the wavelength which gives the maximum growth rate of a small perturbation is found to be about 0.5 r(a), where r(a) is the accretion radius. 16 refs.

• OSTI ID: 6480004
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 358; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
FLUID FLOW
GAS FLOW
PERTURBATION THEORY
STABILITY
STAR ACCRETION
STAR EVOLUTION
STEADY-STATE CONDITIONS
THREE-DIMENSIONAL CALCULATIONS
VISCOSITY
WKB APPROXIMATION