The recently discovered gravitational wave sources GW190521 and GW190814 have
shown evidence of BH mergers with masses and spins outside of the range expected from …

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 …

We separately assess elemental abundances in active galactic nuclei's (AGNs) broad and
narrow emission line regions (BLR and NLR), based on a critical assessment of published …

Context. The changing-look phenomenon observed in a growing number of active galaxies
challenges our understanding of the accretion process close to a black hole. Aims. We …

In this review, the third one in the series focused on a small two-band UV-photometry
mission, we assess possibilities for a small UV two-band photometry mission in studying …

We present the main results from a long-term reverberation mapping campaign carried out
for the Seoul National University AGN Monitoring Project (SAMP). High-quality data were …

Results from a few decades of reverberation mapping (RM) studies have revealed a
correlation between the radius of the broad-line emitting region (BLR) and the continuum …

Before the launch of the Fermi Gamma-ray Space Telescope satellite only two classes of
active galactic nuclei (AGN) were known to generate relativistic jets and thus to emit up to …

Quasars have been proposed as a new class of standard candles analogous to supernovae,
since their large redshift range and high luminosities make them excellent candidates. The …

We present the results from a spectroscopic monitoring campaign to obtain reverberation
mapping measurements and investigate the broad-line region (BLR) kinematics for active …