Detection of AGNs and Quasars with Significant Proper Motions Based on Gaia Data in the SRG/eROSITA Catalog of X-ray Sources
Irtuganov, E. N.; Bikmaev, I. F.; Gilfanov, M. R.; Khamitov, I. M.; Medvedev, P. S.; Sunyaev, R. A.; Gorbachev, M. A.
Russia, Turkey, Germany
Abstract
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 $FX/F_{\textrm{opt}}$-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.