The central nuclei of galaxies, where supermassive black holes (SMBHs) are thought to
reside, can experience phases of activity when they become active galactic nuclei (AGNs) …

A significant fraction of nearby galaxies show evidence of weak nuclear activity unrelated to
normal stellar processes. Recent high-resolution, multiwavelength observations indicate that …

The X‐ray background can be used to constrain the accretion history of supermassive black
holes (SMBHs) in active galactic nuclei (AGN), with the SMBH mass density related to the …

We present a comprehensive synthesis model for the active galactic nuclei (AGN) evolution
and the growth of supermassive black hole (SMBH) in the Universe. We assume that black …

To better understand the prevalence of bulgeless galaxies in the nearby field, we dissect
giant Sc–Scd galaxies with Hubble Space Telescope (HST) photometry and Hobby–Eberly …

The origin of the radio emission in radio-quiet quasars (RQQ) is not established yet. We
present new VLBA observations at 1.6 and 4.9 GHz of 10 RQQ (9 detected), which together …

Abstract The Fundamental Plane of black hole activity is a relation between X-ray luminosity,
radio luminosity and black hole mass for hard-state Galactic black holes and their …

Aims. We present CAIXA, a Catalogue of AGN In the XMM-Newton Archive. It consists of all
the radio-quiet X-ray unobscured ($ N_\mathrm {H}< 2\times10^{22} $ cm-2) active galactic …

We examine unresolved nuclear X-ray sources in 57 brightest cluster galaxies to study the
relationship between nuclear X-ray emission and accretion on to supermassive black holes …

The radio emission in radio-loud quasars originates in a jet carrying relativistic electrons. In
radio-quiet quasars (RQQs) the relative radio emission is∼ 103 times weaker, and its origin …