Rossby wave instability in astrophysical discs

Lovelace, R. V. E.; Romanova, M. M.

doi:10.1088/0169-5983/46/4/041401

Cited by 50 publications

(39 citation statements)

References 73 publications

(127 reference statements)

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“…Many questions remain. For example, how do the Rossby waves affect the protoplanetary disc (Lovelace & Romanova 2014) and how do they affect the evolution of DA white dwarfs and neutron stars (Saio 1982;Berthomieu & Provost 1983;Andersson 1998;Brown & Ushomirsky 2000)?…”

Section: Introductionmentioning

confidence: 99%

Period spacings of γ Doradus pulsators in the Kepler field: Rossby and gravity modes in 82 stars

Reeth

Bedding

et al. 2019

Monthly Notices of the Royal Astronomical Society

110

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Rossby modes are the oscillations in a rotating fluid, whose restoring force is the Coriolis force. They provide an additional diagnostic to understand the rotation of stars, which complicates asteroseismic modelling. We report 82 γ Doradus stars for which clear period spacing patterns of both gravity and Rossby modes have been detected. The period spacings of both show a quasi-linear relation with the pulsation period but the slope is negative for the gravity modes and positive for the Rossby modes. Most Rossby modes have k = −2, m = −1. For only one star a series of k = −1, m = −1 modes is seen. For each pattern, the mean pulsation period, the mean period spacing, and the slope are measured. We find that the slope correlates with the mean period for Rossby mode patterns. The traditional approximation of rotation is used to measure the near-core rotation rate, assuming the star rotates rigidly. We report the near-core rotation rates, the asymptotic period spacings, and the radial orders of excited modes of these 82 main-sequence stars. The near-core rotation rates lie between 0.6 d −1 and 2.3 d −1 . Six stars show surface rotation modulations, among which only KIC 3341457 shows differential rotation while the other five stars have uniform rotations. The radial orders of excited modes show different distributions for the dipole and quadrupole gravity modes versus the Rossby modes.

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Section: Introductionmentioning

confidence: 99%

Period spacings of γ Doradus pulsators in the Kepler field: Rossby and gravity modes in 82 stars

Reeth

Bedding

et al. 2019

Monthly Notices of the Royal Astronomical Society

110

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“…NL Rossby wave interaction is an important mechanism in the evolution of central scenarios in atmospheric, oceanic and astrophysical fluid dynamics e.g., [13][14][15][16][17], yet, to the best of our knowledge, no explicit mechanistic CRW analysis exists to describe NL wave-wave interactions. In order to study the basic nature of the phenomenon, we choose a simple setup of a shear layer (Fig.…”

mentioning

confidence: 99%

On the nonnormal–nonlinear interaction mechanism between counter-propagating Rossby waves

Tamarin-Brodsky

Heifetz

Umurhan

et al. 2015

Theor. Comput. Fluid Dyn.

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The counter-propagating Rossby wave perspective to shear flow instability is extended here to the weakly nonlinear phase. The nonlinear action at a distance interaction mechanism between a pair of waves is identified and separated from the linear one. In the former, the streamwise velocity converges the far-field vorticity anomaly of the opposed wave, whereas in the latter, the cross-stream velocity advects the far-field mean vorticity. A truncated analytical model of two vorticity interfaces shows that higher harmonics generated by the nonlinear interaction act as a forcing on the nonnormal linear dynamics. Furthermore, an intrinsic positive feedback toward small-scale enstrophy results from the fact that higher harmonic pair of waves are generated in anti-phase configuration which is favored for nonnormal growth. Near marginal stability, the waves preserve their structure and numerical simulations of the weakly nonlinear interaction show wave saturation into finite amplitudes, in good agreement both with the fixed point solution of the truncated model, as well as with its corresponding weakly nonlinear Ginzburg-Landau amplitude equation.

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“…Here we will review the salient points that makes the RWI a good candidate to explain the HFQPOs observed in microquasars. See Lovelace & Romanova (2014) for a full review of the RWI in its different domain of application.…”

Section: The Rossby Wave Instability As a Model For Hfqposmentioning

confidence: 99%

Rossby wave instability and high-frequency quasi-periodic oscillations in accretion discs orbiting around black holes

Casse

Vincent

2019

A&A

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Context. The rather elusive High-Frequency Quasi-Periodic Oscillations(HFQPO) observed in the X-ray lightcurve of black hole have been seen in a wide range of frequencies, even within one source. It is also notable to have been detected in 'pairs' of HFQPOs with a close to integer ratio between the frequencies.Aims. The aim of this paper is to investigate some of the possible observable that we could obtain from the having the Rossby Wave Instability (RWI) active in the accretion disc surrounding the compact object.Methods. Using the newly developed GR-AMRVAC code able to follow the evolution of the RWI in a full general relativistic framework, we explore how RWI can reproduce observed HFQPO frequencies ratios and if it is compatible with the observations. In order to model the emission coming from the disc we have linked our general relativistic simulations to the general relativistic ray-tracing GYOTO code and delivered synthetic observables that can be confronted to actual data from binary systems hosting HFQPOs.Results. We have demonstrated in our study that some changes in the physical conditions prevailing in the part of the disc where RWI can be triggered leads to various dominant RWI modes whose ratio recovers frequency ratios observed in various X-ray varniere@apc.univ-paris7.fr Article number, page 1 of 17 arXiv:1905.03984v1 [astro-ph.HE] 10 May 2019Varniere, Casse & Vincent: GR RWI and HFQPOs observables around black holes binary systems. In addition we have also highlighted that when RWI is triggered near the last stable orbit of a spinning black hole, the amplitude of the X-ray modulation increases with the the spin of the black hole. Revisiting published data on X-ray binary systems, we show that this type of relationship actually exists in the five systems where an indirect measure of the spin of the black hole is available.

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Rossby wave instability in astrophysical discs

Cited by 50 publications

References 73 publications

Period spacings of γ Doradus pulsators in the Kepler field: Rossby and gravity modes in 82 stars

Period spacings of γ Doradus pulsators in the Kepler field: Rossby and gravity modes in 82 stars

On the nonnormal–nonlinear interaction mechanism between counter-propagating Rossby waves

Rossby wave instability and high-frequency quasi-periodic oscillations in accretion discs orbiting around black holes

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