Co-existence of Internal Gravity Waves and Tayler-Spruit Magnetic Fields in the Radiative Core of Low-mass Stars

Abstract

The Tayler-Spruit dynamo (TSD) is able to generate a small-scale magnetic field in the differentially rotating stably stratified layers of stars and was recently observed in numerical simulations. In parallel, the propagation of internal gravity waves in stars can be modified in the presence of a magnetic field. Here we first want to estimate the interaction between a magnetic field generated by the TSD and internal gravity waves in the radiative core of low-mass stars. This allows us to then characterise the effect of this interplay on the observed standing modes spectrum and on the internal transport of angular momentum by progressive waves. To do this, we use the STAREVOL evolution code to compute the structure of low-mass rotating stars along their evolution. In particular, we implement a formalism to describe the TSD and estimate the regions where the generated magnetic field is strong enough to change the identity of internal gravity waves to magneto-gravity waves. In addition, we evaluate the possible limitation of angular momentum transport by the combined action of rotation and magnetism. We show that along the pre-main sequence and main-sequence evolution, the lowest frequencies of the excited gravity wave spectrum could be converted to magneto-gravity waves by the magnetic field generated by the TSD. During the red-giant branch we find that most of the excited spectrum of progressive internal gravity waves could be converted into magneto-gravity waves in the very central region.

11 pages, 6 figures, Re-Submitted to A&A (version after 1st review by the referee)

References in corpus (45)

• Slowing the Spins of Stellar Cores
• The Mass-Dependence of Angular Momentum Evolution in Sun-Like Stars
• On magnetic instabilities and dynamo action in stellar radiation zones
• The interior rotation of a sample of gamma Doradus stars from ensemble modelling of their gravity mode period spacings
• A new asteroseismic diagnostic for internal rotation in $\gamma$ Doradus stars
• Diagnoses to unravel secular hydrodynamical processes in rotating main sequence stars
• Angular Momentum Transport via Internal Gravity Waves in Evolving Stars
• Magnetic confinement of the solar tachocline: II. Coupling to a convection zone
• 30 to 100-kG magnetic fields in the cores of red giant stars
• Theoretical seismology in 3D : nonlinear simulations of internal gravity waves in solar-like stars
• Angular momentum redistribution by mixed modes in evolved low-mass stars. II. Spin-down of the core of red giants induced by mixed modes
• Asteroseismology of evolved stars to constrain the internal transport of angular momentum II. Test of a revised prescription for transport by the Tayler instability
• Can plume-induced internal gravity waves regulate the core rotation of subgiant stars?
• Seismic evidence for near solid-body rotation in two Kepler subgiants and implications for angular momentum transport
• Rotation rate of the solar core as a key constraint to magnetic angular momentum transport in stellar interiors
• First evidence of inertial modes in $\gamma$ Doradus stars: The core rotation revealed
• Asteroseismology of evolved stars to constrain the internal transport of angular momentum. I. Efficiency of transport during the subgiant phase
• Strong magnetic fields detected in the cores of 11 red giant stars using gravity-mode period spacings
• Magnetic signatures on mixed-mode frequencies. I. An axisymmetric fossil field inside the core of red giants
• Conversion of Internal Gravity Waves into Magnetic Waves
• Asteroseismic inference of the near-core magnetic field strength in the main sequence B star HD 43317
• Rotation in stellar interiors: General formulation and an asteroseismic-calibrated transport by the Tayler instability
• Angular momentum transport by internal gravity waves III - Wave excitation by core convection and the Coriolis effect
• Sensitivity analysis of the solar rotation to helioseismic data from GONG, GOLF and MDI observations
• Further Evidence of Modified Spin-down in Sun-like Stars: Pileups in the Temperature-Period Distribution
• Spin-down by dynamo action in simulated radiative stellar layers
• Dynamical tide in stellar radiative zones. General formalism and evolution for low-mass stars
• Effect of a strong magnetic field on gravity-mode period spacings in red giant stars
• Asteroseismic measurement of core and envelope rotation rates for 2006 red giant branch stars
• Asteroseismic Signatures of Core Magnetism and Rotation in Hundreds of Low-Luminosity Red Giants
• Angular momentum transport by magnetic fields in main sequence stars with Gamma Doradus pulsators
• Topology and obliquity of core magnetic fields in shaping seismic properties of slowly rotating evolved stars
• Asymmetries of frequency splittings of dipolar mixed modes: a window on the topology of deep magnetic fields
• Asteroseismic g-mode period spacings in strongly magnetic rotating stars
• Gravity waves in strong magnetic fields
• Magnetic signatures on mixed-mode frequencies. II. Period spacings as a probe of the internal magnetism of red giants
• Attempts to reproduce the rotation profile of the red giant KIC 7341231 observed by Kepler
• Detecting deep axisymmetric toroidal magnetic fields in stars. The traditional approximation of rotation for differentially rotating deep spherical shells with a general azimuthal magnetic field
• Period spacing of gravity modes strongly affected by rotation. Going beyond the traditional approximation
• Evidence of structural discontinuities in the inner core of red-giant stars
• Expanding the frontiers of cool-dwarf asteroseismology with ESPRESSO. Detection of solar-like oscillations in the K5 dwarf $\epsilon$ Indi
• Asteroseismology of evolved stars to constrain the internal transport of angular momentum. V. Efficiency of the transport on the red giant branch and in the red clump
• Tayler-Spruit dynamo in stably stratified rotating fluids: Application to proto-magnetars
• Weakened Magnetic Braking Signals the Collapse of the Global Stellar Dynamo
• Nonlinear internal waves breaking in stellar radiation zones. Parametrisation for the transport of angular momentum: bridging geophysical to stellar fluid dynamics