Core overshoot constrained by the absence of a solar convective core and some solar-like stars

Abstract

Convective-core overshoot mixing is a significant uncertainty in stellar evolution. Because numerical simulations and turbulent convection models predict exponentially decreasing radial rms turbulent velocity, a popular treatment of the overshoot mixing is to apply a diffusion process with exponentially decreasing diffusion coefficient. It is important to investigate the parameters of the diffusion coefficient because they determine the efficiency of the mixing in the overshoot region. In this paper, we have investigated the effects of the core overshoot mixing on the properties of the core in solar models and have constrained the parameters of the overshoot model by using helioseismic inferences and the observation of the solar 8B neutrino flux. For solar-mass stars, the core overshoot mixing helps to prolong the lifetime of the convective core developed at the ZAMS. If the strength of the mixing is sufficiently high, the convective core in a solar model could survive till the present solar age, leading to large deviations of the sound-speed and density profiles comparing with the helioseismic inferences. The 8B neutrino flux also favours a radiative solar core. Those provide a constraint on the parameters of the exponential diffusion model of the convective overshoot mixing. A limited asteroseismic investigation of 13 Kepler low-mass stars with 1.0 < M < 1.5 shows a mass-dependent range of the overshoot parameter. The overshoot mixing processes for different elements are analyzed in detail. It is found that the exponential diffusion overshoot model leads to different effective overshoot mixing lengths for elements with different nuclear equilibrium timescale.

arXiv comment19 pages, 14 figures, accepted for publication in MNRAS

References in corpus (62)

• The chemical composition of the Sun
• Modules for Experiments in Stellar Astrophysics (MESA)
• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• A large stellar evolution database for population synthesis studies. I. Scaled solar models and isochrones
• Low Temperature Opacities
• Solar fusion cross sections II: the pp chain and CNO cycles
• The chemical make-up of the Sun: A 2020 vision
• The Victoria-Regina Stellar Models: Evolutionary Tracks and Isochrones for a Wide Range in Mass and Metallicity that Allow for Empirically Constrained Amounts of Convective Core Overshooting
• A new Generation of Standard Solar Models
• Turbulent Convection in Stellar Interiors. I. Hydrodynamic Simulation
• The Updated BaSTI Stellar Evolution Models and Isochrones: I. Solar Scaled Calculations
• New Solar Composition: The Problem With Solar Models Revisited
• A Revised Effective Temperature Scale for the Kepler Input Catalog
• Accurate parameters of 93 solar-type Kepler targets
• Tight asteroseismic constraints on core overshooting and diffusive mixing in the slowly rotating pulsating B8.3V star KIC 10526294
• Internal mixing of rotating stars inferred from dipole gravity modes
• The influence of atomic diffusion on stellar ages and chemical tagging
• Fresh insights on the structure of the solar core
• The spectroscopic Hertzsprung-Russell diagram of Galactic massive stars
• A more realistic representation of overshoot at the base of the solar convective envelope as seen by helioseismology
• Measuring the extent of convective cores in low-mass stars using Kepler data: towards a calibration of core overshooting
• Solar structure and evolution
• Beyond Mixing-length Theory: a step toward 321D
• Updated determination of the solar neutrino fluxes from solar neutrino data
• The dependence of convective core overshooting on stellar mass: Additional binary systems and improved calibration
• The dependence of convective core overshooting on stellar mass: semi-empirical determination using the diffusive approach with two different element mixtures
• Globular Cluster Systems in Brightest Cluster Galaxies: A Near-Universal Luminosity Function?
• Definitive Sun-as-a-star p-mode frequencies: 23 years of BiSON observations
• Uncertainties on near-core mixing in red-clump stars: effects on the period spacing and on the luminosity of the AGB bump
• 3D Hydrodynamic Simulations of Carbon Burning in Massive Stars
• Fundamental Parameters of Main-Sequence Stars in an Instant with Machine Learning
• The dependence of convective core overshooting on stellar mass: reality check, and additional evidence
• OP data on CD for mean opacities and radiative accelerations
• Impacts of radiative accelerations on solar-like oscillating main-sequence stars
• Rotation of the convective core in $\gamma$ Dor stars measured by dips in period spacings of g modes coupled with inertial modes
• Alive and well: a short review about standard solar models
• Convective core entrainment in 1D main sequence stellar models
• Element abundance ratios in the quiet Sun transition region
• ${}^3$He Transport in the Sun and the Solar Neutrino Problem
• The Aarhus Red Giants Challenge I: Stellar structures in the red giant branch phase
• Kepler red-clump stars in the field and in open clusters: constraints on core mixing
• Dependence of Convective Boundary Mixing on Boundary Properties and Turbulence Strength
• Seismic measurement of the locations of the base of convection zone and helium ionization zone for stars in the {\it Kepler} seismic LEGACY sample
• Solar models with convective overshoot, the solar-wind mass loss, and a PMS disk accretion: helioseismic quantities, Li depletion and neutrino fluxes
• Survival of a convective core in low-mass solar-like pulsator HD 203608
• Combining multiple structural inversions to constrain the Solar modelling problem
• Empirical Constraints on Convective Core Overshoot
• Helium settling in F stars: constraining turbulent mixing using observed helium glitch signature
• Turbulent convection model in the overshooting region: II. Theoretical analysis
• Probing core overshooting using subgiant asteroseismology: the case of KIC10273246
• Convective overshoot mixing in stellar interior models
• Sound-speed inversion of the Sun using a nonlocal statistical convection theory
• Applications of the $k$-$\omega$ model in stellar evolutionary models
• New Insights for High-precision Asteroseismology: Acoustic Radius of KIC 6225718
• The solar abundance problem: the effect of the turbulent kinetic flux on the solar envelope model
• Asteroseismic analysis of Kepler target KIC 2837475
• The YNEV stellar evolution and oscillation code
• Local heating due to convective overshooting and the solar modelling problem
• Upward Overshooting in Turbulent Compressible Convection. III. Calibrate Parameters for One-dimensional Reynolds Stress Model
• A Mixed Solar Core, Solar Neutrinos and Helioseismology
• Numerical integral of resistance coefficients in diffusion
• Probing core overshooting using asteroseismology

Cited by in corpus (3)

• Impact of central mixing scheme and nuclear reaction network on the extent of convective cores
• Asteroseismic investigation on KIC 10526294 to probe convective core overshoot mixing
• Inferring the efficiency of convective-envelope overshooting in Red Giant Branch stars