Asteroseismology of $\delta$ Scuti stars: emulating model grids using a neural network

Abstract

Young $\delta$ Scuti stars have proven to be valuable asteroseismic targets but obtaining robust uncertainties on their inferred properties is challenging. We aim to quantify the random uncertainties in grid-based modelling of $\delta$ Sct stars. We apply Bayesian inference using nested sampling and a neural network emulator of stellar models, testing our method on both simulated and real stars. Based on results from simulated stars we demonstrate that our method can recover plausible posterior probability density estimates while accounting for both the random uncertainty from the observations and neural network emulation. We find that the posterior distributions of the fundamental parameters can be significantly non-Gaussian, multi-modal, and have strong covariance. We conclude that our method reliably estimates the random uncertainty in the modelling of $\delta$ Sct stars and paves the way for the investigation and quantification of the systematic uncertainty.

arXiv comment10 pages, 10 figures, 2 tables, published in Monthly Notices of the Royal Astronomical Society 01/09/2023

References in corpus (42)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• emcee: The MCMC Hammer
• The chemical composition of the Sun
• Modules for Experiments in Stellar Astrophysics (MESA)
• The Transiting Exoplanet Survey Satellite
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• The Ages of Stars
• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• The Kepler characterization of the variability among A- and F-type stars. I. General overview
• The Big Problems in Star Formation: the Star Formation Rate, Stellar Clustering, and the Initial Mass Function
• Calculating asteroseismic diagrams for solar-like oscillations
• COSMOPOWER: emulating cosmological power spectra for accelerated Bayesian inference from next-generation surveys
• {\em Gaia}-derived luminosities of {\em Kepler} A/F stars and the pulsator fraction across the δ Scuti instability strip
• Characterising the observational properties of δ Sct stars in the era of space photometry from the Kepler mission
• The first view of $\delta$ Scuti and $\gamma$ Doradus stars with the TESS mission
• Pulsation frequency distribution in Delta Scuti stars
• Very regular high-frequency pulsation modes in young intermediate-mass stars
• Direct Imaging and Astrometric Detection of a Gas Giant Planet Orbiting an Accelerating Star
• The star formation history of Upper Scorpius and Ophiuchus
• The GALAH Survey: Chemodynamics of the Solar Neighbourhood
• A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper-Centaurus Lupus
• The Age and Interior Rotation of Stars from Asteroseismology
• Precise surface gravities of $\delta$ Scuti stars from asteroseismology
• Lithium depletion boundary, stellar associations, and Gaia
• Revisiting bright delta Scuti stars and their period-luminosity relation with TESS and Gaia DR3
• TESS observations of the Pleiades cluster: a nursery for delta Scuti stars
• Highlights of Discoveries for $\delta$ Scuti Variable Stars From the Kepler Era
• SPYGLASS. III. The Fornax-Horologium Association and its Traceback History within the Austral Complex
• Five young $\delta$ Scuti stars in the Pleiades seen with Kepler/K2
• Deep Learning Applied to the Asteroseismic Modeling of Stars with Coherent Oscillation Modes
• Chronostar. II. Kinematic age and substructure of the Scorpius-Centaurus OB2 association
• Hierarchically modelling Kepler dwarfs and subgiants to improve inference of stellar properties with asteroseismology
• Pulsational instability of pre-main sequence models from accreting protostars. I. Constraining the input physics for accretion with spectroscopic parameters and stellar pulsations
• SPYGLASS. II. The Multi-Generational and Multi-Origin Star Formation History of Cepheus Far North
• CoRoT 102749568: mode identification in a delta Scuti star based on regular spacings
• A grid of 200,000 models of young $\delta$ Scuti stars using MESA and GYRE

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