Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/235635

Title

Alpha-viscosity effects in slender tori

Author(s)

Horak, Jin;  Abramowicz, Marek A.;  Levin, Lina;  Slapak, Rikard;  Straub, Odele

Abstract

We explore effects of the Shakura–Sunyaev ˛-viscosity on the dynamics and oscillations of slender tori. We start with a slow secular evolution of the torus. We show that the angular-momentum profile approaches the Keplerian one on a timescale longer than a dynamical one by a factor on the order of 1=˛. We then focus our attention on the oscillations of the torus. We discuss the effects of various angular-momentum distributions. Using a perturbation theory, we have found a rather general result that the high-order acoustic modes are damped by the viscosity, while the high-order inertial modes are enhanced. We calculate viscous growth rates for the lowest-order modes, and show that already the lowest-order inertial mode is unstable for less-steep angular-momentum profiles, or very close to the central gravitating object.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Publications of the Astronomical Society of Japan, Vol. 64, no. 4 (Aug 2012), p. 76

Publication year

2012

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

Accretion disks;  Binaries;  Slender tori;  Viscosity;  X-rays

Publisher

Astronomical Society of Japan

ISSN

0004-6264

Publisher URL

http://pasj.asj.or.jp/v64/n4/640076/640076a.html

Copyright

Copyright © 2012. Astronomical Society of Japan.

Additional information

The authors acknowledge support from the Grant Agency of the Czech Republic (project no. P209/11/2004), the Czech CZ. 1.07/2.300/20.0071 'Synergy' grant supporting international collaboration of IF Opava, and the Polish NCN grant UMO-2011/01/B/ST9/05439.

Peer reviewed