Gaia Early Data Release 3 -- Catalogue validation
  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.
