This review describes recent developments related to the unified model of active galactic
nuclei (AGNs). It focuses on new ideas about the origin and properties of the central …

Active galactic nuclei (AGN) are powered by the accretion of material onto a supermassive
black hole (SMBH) and are among the most luminous objects in the Universe. However, the …

Hard X-ray (≥ 10 keV) observations of active galactic nuclei (AGNs) can shed light on some
of the most obscured episodes of accretion onto supermassive black holes. The 70-month …

In this paper, we provide updated constraints on the bolometric quasar luminosity function
(QLF) from z= 0 to z= 7. The constraints are based on an observational compilation that …

We combine results from deep ALMA observations of massive (M*> 10 10 M⊙) galaxies at
different redshifts to show that the column density of their interstellar medium (ISM) rapidly …

We present the catalog of sources detected in 70 months of observations with the Burst Alert
Telescope (BAT) hard X-ray detector on the Swift gamma-ray burst observatory. The Swift …

Massive black holes (BHs) are at once exotic and yet ubiquitous, residing at the centers of
massive galaxies in the local Universe. Recent years have seen remarkable advances in …

The material surrounding accreting supermassive black holes connects the active galactic
nucleus with its host galaxy and, besides being responsible for feeding the black hole …

The primary source of emission of active galactic nuclei (AGNs), the accretion disc, is
surrounded by an optically and geometrically thick dusty structure ('the so-called dusty …

The majority of the accreting supermassive black holes in the Universe are obscured by
large columns of gas and dust,,. The location and evolution of this obscuring material have …