Gaia Early Data Release 3 -- Catalogue validation

TL;DR

Gaia EDR3 provides highly precise astrometric and photometric data for nearly two billion sources, with validation ensuring data quality and guidance for users, marking a significant improvement over Gaia DR2.

Contribution

This paper presents a comprehensive validation of Gaia EDR3 data, detailing its accuracy, completeness, and recommendations for optimal use, which is a major advancement over previous Gaia data releases.

Findings

Gaia EDR3 shows improved precision and accuracy over Gaia DR2.

Validation identified and addressed data anomalies and systematic errors.

Recommendations enhance the reliability of Gaia EDR3 data usage.

Abstract

The third Gaia data release is published in two stages. The early part, Gaia EDR3, gives very precise astrometric and photometric properties for nearly two billion sources together with seven million radial velocities from Gaia DR2. The full release, Gaia DR3, will add radial velocities, spectra, light curves, and astrophysical parameters for a large subset of the sources, as well as orbits for solar system objects. Before the publication of the catalogue, many different data items have undergone dedicated validation processes. The goal of this paper is to describe the validation results in terms of completeness, accuracy, and precision for the Gaia EDR3 data and to provide recommendations for the use of the catalogue data. The validation processes include a systematic analysis of the catalogue contents to detect anomalies, either individual errors or statistical properties, using statistical analysis and comparisons to the previous release as well as to external data and to models. Gaia EDR3 represents a major step forward, compared to Gaia DR2, in terms of precision, accuracy, and completeness for both astrometry and photometry. We provide recommendations for dealing with issues related to the parallax zero point, negative parallaxes, photometry for faint sources, and the quality indicators.