Barker, AJ orcid.org/0000-0003-4397-7332 and Ogilvie, GI (2014) Hydrodynamic instability in eccentric astrophysical discs. Monthly Notices of the Royal Astronomical Society, 445 (3). pp. 2637-2654. ISSN 0035-8711
Abstract
Eccentric Keplerian discs are believed to be unstable to three-dimensional hydrodynamical instabilities driven by the time-dependence of fluid properties around an orbit. These instabilities could lead to small-scale turbulence, and ultimately modify the global disc properties. We use a local model of an eccentric disc, derived in a companion paper, to compute the non-linear vertical (‘breathing mode’) oscillations of the disc. We then analyse their linear stability to locally axisymmetric disturbances for any disc eccentricity and eccentricity gradient using a numerical Floquet method. In the limit of small departures from a circular reference orbit, the instability of an isothermal disc is explained analytically. We also study analytically the small-scale instability of an eccentric neutrally stratified polytropic disc with any polytropic index using a Wentzel–Kramers–Brillouin (WKB) approximation. We find that eccentric discs are generically unstable to the parametric excitation of small-scale inertial waves. The non-linear evolution of these instabilities should be studied in numerical simulations, where we expect them to lead to a decay of the disc eccentricity and eccentricity gradient as well as to induce additional transport and mixing. Our results highlight that it is essential to consider the three-dimensional structure of eccentric discs, and their resulting vertical oscillatory flows, in order to correctly capture their evolution.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2014, Oxford University Press. This is a pre-copyedited, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The version of record Barker, AJ and Ogilvie, GI (2014) Hydrodynamic instability in eccentric astrophysical discs. Monthly Notices of the Royal Astronomical Society, 445 (3). pp. 2637-2654 is available online at: https://doi.org/10.1093/mnras/stu1939 |
Keywords: | accretion, accretion discs, hydrodynamics, instabilities, waves, planetary systems |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 16 Mar 2017 15:16 |
Last Modified: | 10 May 2019 12:09 |
Published Version: | https://doi.org/10.1093/mnras/stu1939 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/mnras/stu1939 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:108974 |