Convective boundary mixing in low- and intermediate-mass stars I. Core properties from pressure-mode asteroseismology

Abstract

Convective boundary mixing (CBM) is ubiquitous in stellar evolution. It is a necessary ingredient in the models in order to match observational constraints from clusters, binaries and single stars alike. We compute `effective overshoot' measures that reflect the extent of mixing and which can differ significantly from the input overshoot values set in the stellar evolution codes. We use constraints from pressure modes to infer the CBM properties of Kepler and CoRoT main-sequence and subgiant oscillators, as well as in two radial velocity targets (Procyon A and $\alpha$ Cen A). Collectively these targets allow us to identify how measurement precision, stellar spectral type, and overshoot implementation impact the asteroseismic solution. With these new measures we find that the `effective overshoot' for most stars is in line with physical expectations and calibrations from binaries and clusters. However, two F-stars in the CoRoT field (HD 49933 and HD 181906) still necessitate high overshoot in the models. Due to short mode lifetimes, mode identification can be difficult in these stars. We demonstrate that an incongruence between the radial and non-radial modes drives the asteroseismic solution to extreme structures with highly-efficient CBM as an inevitable outcome. Understanding the cause of seemingly anomalous physics for such stars is vital for inferring accurate stellar parameters from TESS data with comparable timeseries length.

20 Pages, 9 Figures, 4 Tables and supplementary material. Accepted for publication in MNRAS

References in corpus (31)

• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• Standing on the shoulders of Dwarfs: the Kepler asteroseismic LEGACY sample II - radii, masses, and ages
• Standing on the shoulders of Dwarfs: the $Kepler$ asteroseismic LEGACY sample I - oscillation mode parameters
• A new correction of stellar oscillation frequencies for near-surface effects
• YREC: The Yale Rotating Stellar Evolution Code
• The Stagger-grid: A grid of 3D stellar atmosphere models - III. The relation to mixing-length convection theory
• A Stellar Model-fitting Pipeline for Asteroseismic Data from the Kepler Mission
• Accurate p-mode measurements of the G0V metal-rich CoRoT target HD 52265
• On the Chemical Mixing Induced by Internal Gravity Waves (IGW)
• On the proper use of the Schwarzschild and Ledoux criteria in stellar evolution computations
• 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
• Solar-like oscillations with low amplitude in the CoRoT target HD 181906
• Asteroseismology of alpha Cen A. Evidence of rotational splitting
• Improvements to Stellar Structure Models, Based on a Grid of 3D Convection Simulations. I. $T(\tau )$-Relations
• Confronting uncertainties in stellar physics: calibrating convective overshooting with eclipsing binaries
• Asteroseismic Signatures of Small Convective Cores
• A Unified tool to estimate Distances, Ages and Masses (UniDAM) from spectrophotometric data
• Non-adiabatic Oscillations of Red Giants
• Diagnostics of Stellar Modelling from Spectroscopy and Photometry of Globular Clusters
• HD 46375: seismic and spectropolarimetric analysis of a young Sun hosting a Saturn-like planet
• Modeling Convective Core Overshoot and Diffusion in Procyon Constrained by Asteroseismic Data
• Theoretical oscillation frequencies for solar-type dwarfs from stellar models with $⟨3\mathrm{D}⟩$-atmospheres
• Surface layer independent model fitting by phase matching: theory and application to HD49933 an HD177153 (aka Perky)
• Mending the structural surface effect of 1D stellar structure models with non-solar metallicities based on interpolated 3D envelopes
• Grid-based seismic modelling at high and low signal-to-noise ratios HD 181420 and HD 175272
• Convective and non-convective mixing in AGB stars
• Asteroseismology of main-sequence F stars with \textit{Kepler}: overcoming short mode lifetimes
• Bayesian inference of stellar parameters based on 1D stellar models coupled with 3D envelopes
• Stellar Parameters in an Instant with Machine Learning: Application to Kepler LEGACY Targets
• Overshooting by differential heating

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• The K2 M67 Study: Precise Mass for a Turnoff Star in the Old Open Cluster M67
• Analysis of high-resolution FEROS spectroscopy for a sample of variable B-type stars assembled from TESS photometry
• Asteroseismic Inversions for Internal Sound Speed Profiles of Main-sequence Stars with Radiative Cores
• Asteroseismic analysis of eight solar-like oscillating evolved stars in the open cluster NGC 6811
• Inverse analysis of asteroseismic data: a review
• Asteroseismic Structure Inversions of Main-Sequence Solar-like Oscillators with Convective Cores
• One size does not fit all: Evidence for a range of mixing efficiencies in stellar evolution calculations