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.

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

References in corpus (23)

• Array Programming with NumPy
• Modules for Experiments in Stellar Astrophysics (MESA)
• The Transiting Exoplanet Survey Satellite
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• 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
• The first view of $\delta$ Scuti and $\gamma$ Doradus stars with the TESS mission
• 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
• A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper-Centaurus Lupus
• 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
• 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
• A grid of 200,000 models of young $\delta$ Scuti stars using MESA and GYRE

Cited by in corpus (5)

• Identifying 850 delta Scuti pulsators in a narrow Gaia colour range with TESS 10-minute full-frame images
• Scalable stellar evolution forecasting: Deep learning emulation vs. hierarchical nearest neighbor interpolation
• Modelling $\delta$ Scuti pulsations: A new grid of p, g, and f modes across pre-main-sequence to post-main-sequence evolution
• Beyond MESA Defaults: The Impact of Structural Resolution Uncertainty in p-mode Asteroseismology
• Emulators for stellar profiles in binary population modeling