2 papers
astro-ph.HE2025
SRG/eROSITA-SDSS view on the relation between X-ray and UV emission for quasars
S. A. Prokhorenko, S. Yu. Sazonov, M. R. Gilfanov +5
Motivated by the idea of using quasars as standardizable candles for cosmology, we examine the relation between X-ray (at 2 keV, ) and ultraviolet (at 2500 Angstrom,…
astro-ph.HE2024
X-Ray Variability of SDSS Quasars Based on the SRG/eROSITA All-Sky Survey
S. A. Prokhorenko, S. Yu. Sazonov, M. R. Gilfanov +6
We examine the long-term (rest-frame time scales from a few months to years) X-ray variability of a sample of 2344 X-ray bright quasars from the SDSS DR14Q Catalogue, bas…