14.1.13 QSO and galaxy candidates
Gaia DR3 includes two tables of extra-galactic sources, or rather candidate sources: qso_candidates and galaxy_candidates. They compile the results from several different pipelines with the philosophy of going for completeness rather than purity. They therefore contain a large fraction of sources which are clearly not extra-galactic, showing, e.g., sources that are rather too bright as seen in Figure 14.35. It is therefore relevant to use the various flags and quality indicators.