Doğan, S. orcid.org/0000-0001-9823-3184 and Nixon, C.J. orcid.org/0000-0002-2137-4146 (Cover date: June 2020) Instability of non-Keplerian warped discs. Monthly Notices of the Royal Astronomical Society, 495 (1). pp. 1148-1157. ISSN 0035-8711
Abstract
Many accretion discs are thought to be warped. Recent hydrodynamical simulations show that (i) discs can break into distinct planes when the amplitude of an imposed warp is sufficiently high and the viscosity sufficiently low, and that (ii) discs can tear up into discrete rings when an initially planar disc is subject to a forced precession. Previously, we investigated the local stability of isolated, Keplerian, warped discs in order to understand the physics causing an accretion disc to break into distinct planes, finding that antidiffusion of the warp amplitude is the underlying cause. Here, we explore the behaviour of this instability in disc regions where the rotation profile deviates from Keplerian. We find that at small warp amplitudes non-Keplerian rotation can stabilize the disc by increasing the critical warp amplitude for instability, while at large warp amplitudes non-Keplerian rotation can lead to an increased growth rate for discs that are unstable. Tidal effects on discs in binary systems are typically weak enough such that the disc remains close to Keplerian rotation. However, the inner regions of discs around black holes are strongly affected, with the smallest radius at which the disc can break into discrete planes being a function of the black hole spin. We suggest that interpreting observed frequencies in the power spectra of light curves from accreting compact objects as nodal and apsidal precession of discrete orbits requires an instability that can break the disc into discrete rings such as the one explored here.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 The Author(s). Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | accretion, accretion discs; black hole physics; hydrodynamics; instabilities |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Nov 2023 14:31 |
Last Modified: | 02 Nov 2023 14:31 |
Status: | Published |
Publisher: | Oxford University Press (OUP) |
Identification Number: | 10.1093/mnras/staa1239 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:204848 |