Strong gravitational lensing of quasars has the potential to unlock the poorly understood
physics of these fascinating objects, as well as serve as a probe of the lensing mass …

The broadening of atomic emission lines by high-velocity motion of gas near accreting
supermassive black holes is an observational hallmark of quasars. Observations of broad …

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 …

Context. Understanding the physics and geometry of accretion and ejection around super
massive black holes (SMBHs) is important to understand the evolution of active galactic …

The broad line region (BLR) in active galactic nuclei (AGNs) is composed of dense gas (∼
1011 cm− 3) on sub-pc scale, which absorbs about 30 per cent of the ionizing continuum …

Recent observations show that the metallicity Z BLR of the broad-line region (BLR) in active
galactic nuclei (AGNs) is solar to supersolar, which is positively correlated with the mass of …

Accretion onto black holes is key to their growth over cosmic time, especially during the
active galactic nuclei phase when the inflowing material forms a radiatively efficient …

The concept of the quasar main sequence is very attractive since it stresses correlations
between various parameters and implies the underlying simplicity. In the optical plane …

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 …

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 …