# Asteroseismic masses, ages, and core properties of $\gamma$ Doradus stars using gravito-inertial dipole modes and spectroscopy

## TL;DR

This study uses gravito-inertial modes and spectroscopy to estimate fundamental parameters of 37 gamma Doradus stars, revealing insights into their core properties, ages, and angular momentum transport during the main sequence.

## Contribution

It introduces multivariate linear models linking observable asteroseismic and spectroscopic data to stellar parameters, improving parameter estimation accuracy for gamma Doradus stars.

## Key findings

- Achieved ~10% uncertainty in stellar mass, age, and core overshooting.
- Found efficient angular momentum transport occurs early in the main sequence.
- Observed Rossby modes across most of the main-sequence phase.

## Abstract

The asteroseismic modelling of period spacing patterns from gravito-inertial modes in stars with a convective core is a high-dimensional problem. We utilise the measured period spacing pattern of prograde dipole gravity modes (acquiring $\Pi_0$), in combination with the effective temperature ($T_{\rm eff}$) and surface gravity ($\log g$) derived from spectroscopy, to estimate the fundamental stellar parameters and core properties of 37 $\gamma~$Doradus ($\gamma~$Dor) stars whose rotation frequency has been derived from $\textit{Kepler}$ photometry. We make use of two 6D grids of stellar models, one with step core overshooting and one with exponential core overshooting, to evaluate correlations between the three observables $\Pi_0$, $T_{\rm eff}$, and $\log g$ and the mass, age, core overshooting, metallicity, initial hydrogen mass fraction and envelope mixing. We provide multivariate linear model recipes relating the stellar parameters to be estimated to the three observables ($\Pi_0$, $T_{\rm eff}$, $\log g$). We estimate the (core) mass, age, core overshooting and metallicity of $\gamma~$Dor stars from an ensemble analysis and achieve relative uncertainties of $\sim\!10$ per cent for the parameters. The asteroseismic age determination allows us to conclude that efficient angular momentum transport occurs already early on during the main sequence. We find that the nine stars with observed Rossby modes occur across almost the entire main-sequence phase, except close to core-hydrogen exhaustion. Future improvements of our work will come from the inclusion of more types of detected modes per star, larger samples, and modelling of individual mode frequencies.