Overstability of axisymmetric oscillations in thin accretion disks

Journal Article · Sat Dec 15 00:00:00 EST 1984 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/162736· OSTI ID:6026433

Blumenthal, G R; Yang, L T; Lin, D N.C.

We examine the stability of geometrically thin and optically thick and thin accretion disks to axisymmetric perturbations. We show that the standard ..cap alpha..-disk models admit not only classical thermal and viscous instabilities, which are generally associated with regions where electron scattering and radiation pressure are dominant, but also radial pulsational instabilities. We derive a general dispersion relationship and examine the eigenvectors' response to local axisymmetric perturbations. These general results are applied for various choices of viscosity, opacity and equation of state. Our results indicate that there are pulsationally overstable regions, which are otherwise thermally and viscously stable. The underlaying physical origin and the implications of these instabilities are discussed. Finally, we speculate that quasi-periodic oscillation found in dwarf nova systems may be a manifestation of these pulsation overstabilities.

• Research Organization: Lick Observatory and Board of Studies in Astronomy and Astrophysics, University of California, Santa Cruz
• OSTI ID: 6026433
• Journal Information: Astrophys. J.; (United States), Vol. 287:2
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
STAR MODELS
STAR ACCRETION
DISPERSION RELATIONS
EIGENVECTORS
EQUATIONS OF STATE
HYDRODYNAMICS
NOVAE
OPACITY
OSCILLATIONS
PLASMA INSTABILITY
PULSATIONS
RADIATION PRESSURE
VISCOSITY
EQUATIONS
ERUPTIVE VARIABLE STARS
FLUID MECHANICS
INSTABILITY
MATHEMATICAL MODELS
MECHANICS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
STAR EVOLUTION
STARS
VARIABLE STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources