14.1 Introduction
Author(s): Claus Fabricius, Xavier Luri
This section summarises the results of the independent validation tests run by the Coordination Unit 9 (CU9) of DPAC on the Gaia DR3 data. It includes the tests already made for Gaia EDR3 for astrometry and photometry, with relevant updates, and adds new results for the many new data products appearing for the first time in Gaia DR3.
The tests described here are to a large extent complementary to the ones published in the validation papers (Fabricius et al. (2021), Babusiaux et al. (2023)) accompanying the early and the final Gaia DR3 releases. These papers provide a more concise overview of the validation findings as well as practical recommendations for the usage of the Gaia DR3 data.
In several cases the issues found during the validation campaign were repaired by reprocessing before the data release; these cases are not discussed here, since they are not of relevance for the published data. For the remaining cases we document the issue and in some cases give recommendations to mitigate them.
Gaia DR3 comprises several dozen tables. Some of them did not go through an independent validation beyond a very basic one. This applies to:
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The tables of simulated data: the GUMS universe model simulation, gaia_universe_model, and the GOG catalogue simulation, gaia_source_simulation;
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Reference frame sources for the astrometric solution, frame_rotator_source;
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Reference frame sources for Gaia-CRF3, cross-id table for selected AGN, agn_cross_id;
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Commanded scan law table, commanded_scan_law;
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Gaia DR2 to Gaia EDR3 match table, also valid for Gaia DR3, dr2_neighbourhood;
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Cross-matches with external catalogues (some 30 tables).