Detection of AGNs and Quasars with Significant Proper Motions Based on Gaia Data in the SRG/eROSITA Catalog of X-ray Sources

Based on a comparison of the SRG/eROSITA catalog of X-ray active stars and the Gaia catalog, we have obtained a sample of 502 peculiar objects for which Gaia, on the one hand, detects statistically significant parallaxes or proper motions and, on the other hand, records signs of a nonzero optical extent. On the FX/Fₒₚₜ –color diagram these objects are significantly separated from the bulk of the stars and are located in the region typical for active galactic nuclei (AGNs). According to the SIMBAD database, ≈50% of them are AGNs and galaxies with spectroscopic redshifts and only ~1.4% are confirmed objects in our Galaxy. Our spectroscopic observations of 19 unidentified objects with the RTT-150 telescope have shown that 18 of them are AGNs at redshifts ~ 0.01–0.3 and one object is an M star in our Galaxy. We discuss various scenarios for the appearance of such peculiar objects.