Gaia/GSP-spec spectroscopic properties of gamma Doradus pulsators

Abstract

The third Data Release of the ESA mission has provided a large sample of new gravity-mode pulsators, among which more than 11,600 are stars. The goal of the present work is to present the spectroscopic parameters of these pulsators estimated by the module that analysed millions of spectra. Such a parametrisation could help confirm their nature and provide their chemo-physical properties. The Galactic positions, kinematics, and orbital properties of these new pulsators were examined in order to define a sub-sample belonging to the Milky Way thin disc, in which these young stars should preferentially be found. The stellar luminosities, radii, and astrometric surface gravities were estimated without adopting any priors from uncertain stellar evolution models. These parameters, combined with the effective temperatures, spectroscopic gravities, and metallicities were then validated by comparison with recent literature studies. Most stars are found to belong to the Galactic thin disc, as expected. It is also found that the derived luminosities, radii, and astrometric surface gravities are high quality and have values typical of genuine pulsators. Moreover, we show that and of pulsators with high enough spectra or slow to moderate rotation rates are robust. This allowed to define a sub-sample of genuine slow-rotating pulsators. Their were found to be between sim 6,500 and sim 7,800 K is around 4.2, and the luminosities and stellar radii peak at sim 5 L$_ and sim 1.7 R$_ The median metallicity is close to the Solar value, although with higher and lower metallicities by about pm 0.5 dex were also identified. The content is fully consistent with the chemical properties of the Galactic disc. spectroscopic properties of stars therefore confirm the nature of these pulsators and allow to chemo-physically parametrise a new large sample of such stars. Moreover, future data releases should drastically increase the number of stars with parameters spectroscopically derived with good precision.