Anisotropic turbulent transport with horizontal shear in stellar radiative zones

Abstract

Context. Turbulent transport in stellar radiative zones is a key ingredient of stellar evolution theory, but the anisotropy of the transport due to the stable stratification and the rotation of these regions is poorly understood. The assumption of shellular rotation, which is a cornerstone of the so-called rotational mixing, relies on an efficient horizontal transport. However, this transport is included in many stellar evolution codes through phenomenological models that have never been tested. Aims. We investigate the impact of horizontal shear on the anisotropy of turbulent transport. Methods. We used a relaxation approximation (also known as τ approximation) to describe the anisotropising effect of stratification, rotation, and shear on a background turbulent flow by computing velocity correlations. Results. We obtain new theoretical scalings for velocity correlations that include the effect of horizontal shear. These scalings show an enhancement of turbulent motions, which would lead to a more efficient transport of chemicals and angular momentum, in better agreement with helio- and asteroseismic observations of rotation in the whole Hertzsprung-Russell diagram. Moreover, we propose a new choice for the non-linear time used in the relaxation approximation, which characterises the source of the turbulence. Conclusions. For the first time, we describe the effect of stratification, rotation, and vertical and horizontal shear on the anisotropy of turbulent transport in stellar radiative zones. The new prescriptions need to be implemented in stellar evolution calculations. To do so, it may be necessary to implement non-diffusive transport.

arXiv comment7 pages, accepted for publication in A&A

References in corpus (40)

• Presupernova Evolution of Differentially Rotating Massive Stars Including Magnetic Fields
• Fast core rotation in red-giant stars revealed by gravity-dominated mixed modes
• Spin down of the core rotation in red giants
• Seismic evidence for a rapidly rotating core in a lower-giant-branch star observed with Kepler
• Seismic constraints on the radial dependence of the internal rotation profiles of six Kepler subgiants and young red giants
• Seismic diagnostics for transport of angular momentum in stars 1. Rotational splittings from the PMS to the RGB
• Angular momentum transport within evolved low-mass stars
• Asteroseismic measurement of surface-to-core rotation in a main sequence A star, KIC 11145123
• The interior rotation of a sample of gamma Doradus stars from ensemble modelling of their gravity mode period spacings
• Angular momentum transport in stellar interiors constrained by rotational splittings of mixed modes in red giants
• White Dwarf Rotation as a Function of Mass and a Dichotomy of Mode Linewidths: Kepler Observations of 27 Pulsating DA White Dwarfs Through K2 Campaign 8
• On shear-induced turbulence in rotating stars
• Seismic evidence for a weak radial differential rotation in intermediate-mass core helium burning stars
• Asteroseismic measurement of slow, nearly-uniform surface-to-core rotation in the main sequence F star KIC 9244992
• Core rotation braking on the red giant branch for various mass ranges
• Transport and mixing in the radiation zones of rotating stars: I-Hydrodynamical processes
• White dwarf spins from low mass stellar evolution models
• On the sensitivity of gravito-inertial modes to differential rotation in intermediate-mass main-sequence stars
• Nearly-uniform internal rotation of solar-like main-sequence stars revealed by space-based asteroseismology and spectroscopic measurements
• Asymptotic g modes: Evidence for a rapid rotation of the solar core
• Understanding angular momentum transport in red giants: the case of KIC 7341231
• Stellar rotation: Evidence for a large horizontal turbulence and its effects on evolution
• γ Doradus stars as test of angular momentum transport models
• The internal rotation profile of the B-type star KIC10526294 from frequency inversion of its dipole gravity modes and statistical model comparison
• The interior angular momentum of core hydrogen burning stars from gravity-mode oscillations
• Turbulent transport in radiative zones of stars
• Anisotropic turbulent transport in stably stratified rotating stellar radiation zones
• Internal rotation of 13 low-mass low-luminosity red giants in the Kepler field
• Shear mixing in stellar radiative zones - II. Robustness of numerical simulations
• Shear mixing in stellar radiative zones I. Effect of thermal diffusion and chemical stratification
• Turbulent transport by diffusive stratified shear flows: from local to global models. Part I: Numerical simulations of a stratified plane Couette flow
• The dynamics of stratified horizontal shear flows at low Péclet number
• Horizontal shear instabilities at low Prandtl number
• Turbulent transport in a strongly stratified forced shear layer with thermal diffusion
• Horizontal shear instabilities in rotating stellar radiation zones: I. Inflectional and inertial instabilities and the effects of thermal diffusion
• Horizontal shear instabilities in rotating stellar radiation zones: II. Effects of the full Coriolis acceleration
• The GSF Instability and Turbulence do not Account for the Relatively Low Rotation Rate of Pulsars
• Turbulent transport by diffusive stratified shear flows: from local to global models. Part II: Limitations of local models
• Magnetic and rotational quenching of the $\Lambda$ effect
• Transport of angular momentum and chemical species by anisotropic mixing in stellar radiative interiors

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