The collective mode and turbulent viscosity in accretion discs

• Published in: Physics letters. A Vol. 317; no. 3; pp. 181 - 198
• Main Authors: Fridman, A.M, Boyarchuk, A.A, Bisikalo, D.V, Kuznetsov, O.A, Khoruzhii, O.V, Torgashin, Yu.M, Kilpio, A.A
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.10.2003
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2003.08.031

The existence of a spiral-vortex structure is revealed by a numerical simulation of the dynamics of an accretion disc in close binary stars. This structure is not related to the tidal influence of a companion star. It is a density wave containing a one-armed spiral and an anticyclonic vortex. The formation of the structure is caused by a hydrodynamical instability. The latter results in a disc turbulence with a turbulent viscosity coefficient ν≃0.035 Ωh 2 ( h is a semithickness of the disc). This value is in accordance with both the value of a numerical viscosity in presented calculations and the results of observations. The period of the density wave rotation is in agreement with the typical periods of light curve variations observed in cataclysmic binary stars.