On the overstability of axisymmetric oscillations in thin accretion disks

Abstract

view Abstract Citations (92) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the overstability of axisymmetric oscillations in thin accretion disks Blumenthal, G. R. ; Lin, D. N. C. ; Yang, L. T. Abstract The stability of geometrically thin and optically thick and thin accretion disks to axisymmetric perturbations is examined. It is shown that the standard 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. A general dispersion relationship is derived, and the eigenvectors' response to local axisymmetric perturbations is examined. These general results are applied for various choices of viscosity, opacity, and equation of state. The 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, it is speculated that quasi-periodic oscillation found in dwarf nova systems may be a manifestation of these pulsation overstabilities. Publication: The Astrophysical Journal Pub Date: December 1984 DOI: 10.1086/162736 Bibcode: 1984ApJ...287..774B Keywords: Accretion Disks; Dwarf Novae; Motion Stability; Optical Thickness; Stellar Mass Accretion; Stellar Oscillations; Axisymmetric Bodies; Differential Equations; Electron Scattering; High Reynolds Number; Laminar Flow; Perturbation Theory; Steady State; Astrophysics full text sources ADS |