Spectroscopic Redshift Determination for a Sample of Distant Quasars Detected by the SRG Observatory Based on RTT-150 Observations. I

Abstract

Results of the first spectroscopic observations at the 1.5-m Russian–Turkish telescope for the X-ray sources discovered by the eROSITA telescope onboard the SRG space observatory and identified by the SRGz machine learning system as candidates for distant X-ray quasars are presented. Seven objects have been confirmed as quasars at redshifts $$z=2.7{-}4.2$$ and two sources, which were included in the program of optical observations aimed at testing and adjusting SRGz and had a significant uncertainty in the photometric redshift, have turned out to be Seyfert galaxies at $$z\approx 0.6$$ .