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 …

We review the properties of the established Scaling Relations (SRs) of galaxies and active
galactic nuclei (AGN), focusing on their origin and expected evolution back in time, providing …

We address the effect of orientation of the accretion disk plane and the geometry of the
broad-line region (BLR) as part of an effort to understand the distribution of quasars in …

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 …

We present a statistical analysis of the optical properties of an X-ray-selected Type 1 active
galactic nucleus (AGN) sample, using high signal-to-noise ratio (S/N> 20) spectra of the …

Optical Fe ii emission is a strong feature in quasar spectra originating in the broad-line
region (BLR). The difficulty in understanding the complex Fe ii pseudo-continuum has led us …

We explore the evolution of the time variability (in the optical g-band and on timescales of
weeks to years) of Sloan Digital Sky Survey Stripe 82 quasars along the quasar main …

We study in detail the inner∼ 600 pc of the Seyfert 2 galaxy ESO 138-G001 by means of the
Soar Integral Field Spectrograph attached to the SOAR telescope. This source is known for …

We address the effect of the viewing angle of the accretion disk plane and the geometry of
the broad-line region (BLR) with the goal of interpreting the distribution of quasars along the …

Context. Eigenvector 1 (EV1) is the formal parameter which allows the introduction of some
order in the properties of the unobscured type 1 active galaxies. Aims. We aim to understand …