The population of hot subdwarf stars studied with Gaia -- IV. Catalogues of hot subluminous stars based on Gaia EDR3

TL;DR

This paper presents updated catalogues of hot subluminous stars based on Gaia EDR3 data, significantly expanding the known populations and improving detection methods, especially in crowded Galactic regions.

Contribution

The authors compiled new Gaia EDR3-based catalogues of hot subluminous stars, increasing the known sample size and refining selection criteria for better detection.

Findings

New catalogue of 6,616 hot subdwarfs with multi-band photometry and astrometry.

Updated Gaia EDR3 catalogue of 61,585 hot subluminous stars, a substantial increase from previous data.

Enhanced detection of hot subluminous stars in crowded Galactic and Magellanic Cloud regions.

Abstract

In light of substantial new discoveries of hot subdwarfs by ongoing spectroscopic surveys and the availability of the Gaia mission Early Data Release 3 (EDR3), we compiled new releases of two catalogues of hot subluminous stars: The data release 3 (DR3) catalogue of the known hot subdwarf stars contains 6,616 unique sources and provides multi-band photometry, and astrometry from Gaia EDR3 as well as classifications based on spectroscopy and colours. This is an increase of 742 objects over the DR2 catalogue. This new catalogue provides atmospheric parameters for 3,087 stars and radial velocities for 2,791 stars from the literature. In addition, we have updated the Gaia Data Release 2 (DR2) catalogue of hot subluminous stars using the improved accuracy of the Gaia EDR3 data set together with updated quality and selection criteria to produce the Gaia EDR3 catalogue of 61,585 hot subluminous stars, representing an increase of 21,785 objects. The improvements in Gaia EDR3 astrometry and photometry compared to Gaia DR2 have enabled us to define more sophisticated selection functions. In particular, we improved hot subluminous star detection in the crowded regions of the Galactic plane as well as in the direction of the Magellanic Clouds by including sources with close apparent neighbours but with flux levels that dominate the neighbourhood.