Astrophysical properties of 15062 Gaia DR3 gravity-mode pulsators

Pulsation amplitudes, rotation, and spectral line broadening^★

¹ Institute of Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
e-mail: conny.aerts@kuleuven.be
² Department of Astrophysics, IMAPP, Radboud University Nijmegen, PO Box 9010, 6500 GL, Nijmegen, The Netherlands
³ Max Planck Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg, Germany
⁴ Guest Researcher, Center for Computational Astrophysics, Flatiron Institute, 162 Fifth Ave, New York, NY 10010, USA
⁵ I-BioStat, Universiteit Hasselt, Martelarenlaan 42, 3500 Hasselt, Belgium
⁶ I-BioStat, KU Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium

Received: 17 December 2022
Accepted: 8 February 2023

Abstract

Context. Gravito-inertial asteroseismology came into existence thanks to high-precision CoRoT and Kepler space photometric light curves. So far, it has given rise to the internal rotation frequency of a few hundred intermediate-mass stars, yet only several tens of these have been weighed, sized, and age-dated with high precision using asteroseismic modelling.

Aims. We aim to increase the sample of optimal targets for future gravito-inertial asteroseismology by assessing the properties of 15062 newly found Gaia DR3 gravity-mode pulsators. We also wish to investigate whether or not there is a connection between their fundamental parameters, the dominant mode, and their spectral line broadening as measured by Gaia.

Methods. After reclassifying about 22% of the F-type gravity-mode pulsators as B-type according to their effective temperature, we constructed histograms of the fundamental parameters and mode properties of the 15062 new Gaia DR3 pulsators. We compared these histograms with those of 63 Kepler bona fide class members. We fit errors-in-variables regression models to couple the effective temperature, luminosity, gravity, and oscillation properties to the two Gaia DR3 parameters capturing spectral line broadening for a fraction of the pulsators.

Results. We find that the selected 15062 gravity-mode pulsators have properties that are fully in line with those of their well-known Kepler analogues, revealing that Gaia has a role to play in asteroseismology. The dominant ɡ-mode frequency is a significant predictor of the spectral line broadening for the class members for which this quantity has been measured. We show that the Gaia vbroad parameter captures the joint effect of time-independent intrinsic and rotational line broadening and time-dependent tangential pulsational broadening.

Conclusions. While the Gaia mission was not designed to detect non-radial oscillation modes, its multitude of data and homogeneous data treatment allow us to identify a vast number of new gravity-mode pulsators that have fundamental parameters and dominant mode properties in agreement with those of such Kepler bona fide pulsators. This large new sample of Gaia DR3 pulsators can be followed up with dedicated high-precision photometric or high-resolution spectroscopic instruments to embark on asteroseismic modelling.