Asteroseismology of evolved stars to constrain the internal transport of angular momentum. I. Efficiency of transport during the subgiant phase

Abstract

Context: The observations of solar-like oscillations in evolved stars have brought important constraints on their internal rotation rates. To correctly reproduce these data, an efficient transport mechanism is needed in addition to meridional circulation and shear instability. Aims: We study the efficiency of the transport of angular momentum during the subgiant phase. Results: The precise asteroseismic measurements of both core and surface rotation rates available for the six Kepler targets enable a precise determination of the efficiency of the transport of angular momentum needed for each of these subgiants. These results are found to be insensitive to all the uncertainties related to the modelling of rotational effects before the post-main sequence phase. An interesting exception in this context is the case of young subgiants (typical values of log(g) close to 4), because their rotational properties are sensitive to the degree of radial differential rotation on the main sequence. These young subgiants constitute therefore perfect targets to constrain the transport of angular momentum on the main sequence from asteroseismic observations of evolved stars. As for red giants, we find that the efficiency of the additional transport process increases with the mass of the star during the subgiant phase. However, the efficiency of this undetermined mechanism decreases with evolution during the subgiant phase, contrary to what is found for red giants. Consequently, a transport process with an efficiency that increases with the degree of radial differential rotation cannot account for the core rotation rates of subgiants, while it correctly reproduces the rotation rates of red giant stars. This suggests that the physical nature of the additional mechanism needed for the internal transport of angular momentum may be different in subgiant and red giant stars.

10 pages, 11 figures, accepted for publication in A&A

References in corpus (5)

• Angular Momentum Transport via Internal Gravity Waves in Evolving Stars
• Constraining the efficiency of angular momentum transport with asteroseismology of red giants: the effect of stellar mass
• Angular momentum redistribution by mixed modes in evolved low-mass stars. II. Spin-down of the core of red giants induced by mixed modes
• Can plume-induced internal gravity waves regulate the core rotation of subgiant stars?
• Near-degeneracy effects on the frequencies of rotationally-split mixed modes in red giants

Cited by in corpus (40)

• Age dissection of the Milky Way discs: red giants in the Kepler field
• The mass discrepancy in intermediate- and high-mass eclipsing binaries: the need for higher convective core masses
• Asteroseismology of evolved stars to constrain the internal transport of angular momentum II. Test of a revised prescription for transport by the Tayler instability
• 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
• Constraining stellar evolution theory with asteroseismology of $\gamma$ Doradus stars using deep learning
• Probing the temperature gradient in the core boundary layer of stars with gravito-inertial modes: the case of KIC7760680
• Magnetic signatures on mixed-mode frequencies. I. An axisymmetric fossil field inside the core of red giants
• A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper-Centaurus Lupus
• The effects of surface fossil magnetic fields on massive star evolution: II. Implementation of magnetic braking in MESA and implications for the evolution of surface rotation in OB stars
• Lithium depletion and angular momentum transport in solar-type stars
• Rotation in stellar interiors: General formulation and an asteroseismic-calibrated transport by the Tayler instability
• Asteroseismology of 36 \emph{Kepler} subgiants -- I. Oscillation frequencies, linewidths and amplitudes
• Asteroseismic measurement of core and envelope rotation rates for 2006 red giant branch stars
• Lithium depletion and angular momentum transport in F-type and G-type stars in Galactic open clusters
• Magnetic signatures on mixed-mode frequencies. II. Period spacings as a probe of the internal magnetism of red giants
• The magneto-rotational instability in massive stars
• Asteroseismology of evolved stars to constrain the internal transport of angular momentum. IV. Internal rotation of Kepler 56 from an MCMC analysis of the rotational splittings
• Testing angular momentum transport processes with asteroseismology of solar-type main-sequence stars
• 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
• Asteroseismology of evolved stars to constrain the internal transport of angular momentum. VI. Testing a parametric formulation for the azimuthal magneto-rotational instability
• Backtracing the internal rotation history of the $\beta$ Cep star HD 129929
• Inferring the velocity of early massive stars from the abundances of extremely metal-poor stars
• Angular momentum transport, layering, and zonal jet formation by the GSF instability: nonlinear simulations at a general latitude
• Three-Dimensional Simulations of Massive Stars: II. Age Dependence
• Angular momentum transport in a contracting stellar radiative zone embedded in a large scale magnetic field
• Tayler-Spruit dynamo in stably stratified rotating fluids: Application to proto-magnetars
• Photometric White Dwarf Rotation
• Coralie radial-velocity search for companions around evolved stars (CASCADES) III. A new Jupiter host-star: in-depth analysis of HD 29399 using TESS data
• Amplitude of solar gravity modes generated by penetrative plumes
• Angular momentum and lithium transport from main sequence to sub-giant and red giant low-mass stars
• Evolving massive stars to core collapse with GENEC: Extension of equation of state, opacities and effective nuclear network
• Constraining differential rotation in gamma Doradus stars from inertial dips properties
• Constraining the Rotation Profile in a Low-Luminosity Subgiant with a Surface Rotation Measurement
• Automated all-sky detection of γ Doradus / δ Scuti hybrids in TESS data from positive unlabelled (PU) learning
• Impact of tides on non-coplanar orbits of progenitors of high-mass X-ray binaries
• The impact of a fossil magnetic field on dipolar mixed-mode frequencies in sub- and red-giant stars
• Perspectives on the Physics of Late-Type Stars from Beyond Low Earth Orbit, the Moon and Mars
• Co-existence of Internal Gravity Waves and Tayler-Spruit Magnetic Fields in the Radiative Core of Low-mass Stars
• Modelling differential rotation of red giants: the case of the evolved sun