Optical Spectroscopy of Quasars Discovered by SRG/eROSITA with a 2.5-m Telescope at the Caucasus Mountain Observatory of SAI MSU

• Published in: Astronomy letters 2021-10, Vol.47 (10), p.661-673
• Main Authors: Dodin, A. V., Shatsky, N. I., Belinski, A. A., Atapin, K. E., Burlak, M. A., Zheltoukhov, S. G., Tatarnikov, A. M., Postnov, K. A., Cherepashchuk, A. M., Belvedersky, M. I., Borisov, V. D., Burenin, R. A., Gilfanov, M. R., Krivonos, R. A., Medvedev, P. S., Meshcheryakov, A. V., Sazonov, S. Yu, Sunyaev, R. A., Khorunzhev, G. A.
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Astroparticles; Black holes; Bolometers; Emission lines; Luminosity; Mountains; Observations and Techniques; Observatories; Physics; Physics and Astronomy; Quasars; Sky surveys (astronomy); Space telescopes; Spectroscopy; Supermassive black holes; X-ray astronomy
• ISSN: 1063-7737; 1562-6873
• DOI: 10.1134/S1063773721100029

Based on observations with the transient double-beam spectrograph (TDS) at the 2.5-m telescope of the Caucasus Mountain Observatory of SAI MSU, we have determined the redshifts for 15 new quasars detected in X-rays by the eROSITA telescope of the SRG orbital observatory during the first three all-sky surveys. The redshifts of the sources lie in the range 0.5–4.156. We have estimated the masses of the central supermassive black holes and the bolometric luminosities for eight quasars from the width of the C IV 1549 Å emission line and the continuum flux at 1350 Å. For these objects we have also estimated the ratio of the X-ray luminosity to the Eddington limit to be a few percent. At the same time, the bolometric-to-Eddington luminosity ratio for them has turned out to be in a fairly narrow range, 30–40 . A large ratio points to an active growth of the mass of the central black holes in these objects.