A landmark of accretion processes in active galactic nuclei (AGN) is the continuum
originating from a complex structure, ie, an accretion disk and a corona around a …

It is well known that reverberation mapping of active galactic nuclei (AGNs) reveals a
relationship between AGN luminosity and the size of the broad-line region, and that use of …

The radius–luminosity () relationship of active galactic nuclei (AGNs) established by the
reverberation mapping (RM) observations has been widely used as a single-epoch black …

Abstract We use the Panoramic Survey Telescope and Rapid Response System 1 Survey
(Pan-STARRS1, PS1) data to extend the Sloan Digital Sky Survey (SDSS) Stripe 82 quasar …

The investigation of emission line regions within active galaxies (AGNs) has a rich and
extensive history, now extending to the use of AGNs and quasars as “standardizable” …

A soft X-ray excess above the 2–10 keV power-law extrapolation is generally observed in
the X-ray spectra of active galactic nuclei. The origin of this excess is still not well …

Context. The Vera Rubin Observatory will provide an unprecedented set of time-dependent
observations of the sky. The planned Legacy Survey of Space and Time (LSST), operating …

Context. Thanks to the advent of large-scale optical surveys, a diverse set of flares from the
nuclear regions of galaxies has recently been discovered. These include the disruption of …

We present an analysis of UV spectra of 13 quasars believed to belong to extreme
Population A (xA) quasars, aimed at the estimation of the chemical abundances of the broad …

The open problems related to cosmological tensions in current times have opened new
paths to study new probes to constrain cosmological parameters in standard and extended …