Gaia DR3. spurious signals

Numerical simulations in which period search is performed on Gaia time series with a scan-angle dependent signal qualitatively reproduce the general structure observed in the spurious period distribution of photometry and astrometry, as well as the associated spatial distributions on the sky. A variety of statistics allows for the deeper understanding and identification of affected sources. The origin of the scan-angle dependent signals and subsequent spurious periods is well-understood and is in majority caused by fixed-orientation optical pairs with separation <0.5" (amongst which binaries with P>>5y) and (cores of) distant galaxies.

Though the majority of sources with affected derived parameters have been filtered out from the Gaia archive nss_two_body_orbit and several vari-tables, there remain Gaia DR3 data that should be treated with care (note that no sources were filtered from gaia_source). Finally, the various statistics discussed in the paper can not only be used to identify and filter affected sources, but alternatively reveal new information about them not available through other means, especially in terms of binarity on sub-arcsecond scale.