Related papers: Black holes in Active Galactic Nuclei: observation…
The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured Active Galactic Nuclei…
The radio-loud AGN unification model associates powerful radio galaxies with radio-loud quasars and blazars. In analogy with the radio-quiet scheme, the nuclear regions of objects showing only narrow emission lines in their optical spectrum…
Microquasars provide new insights into: 1) the physics of relativistic jets from black holes, 2) the connection between accretion and ejection, and 3) the physical mechanisms in the formation of stellar-mass black holes. Furthermore, the…
Massive Black Holes detected in the centers of many nearby galaxies show an approximately linear relation with the luminosity of the host bulge, with the black hole mass being 0.001-0.002 of the bulge mass. Previous work suggested that…
We analyze Hubble Space Telescope (HST) optical imaging of eight low-mass galaxies hosting active galactic nuclei (AGN) identified via their photometric variability in \cite{baldassare_search_2020}. We use GALFIT to model the 2D galaxy…
Active Galactic Nuclei are fueled from material (gas or stars) that are in general far away from the gravitational influence of the central black hole, the engine thought to be responsible for their activity. The required material has a lot…
We present a detailed study of the optical spectroscopic properties of 12 active galactic nuclei (AGNs) with candidate low-mass black holes (BHs) selected by Kamizasa et al. through rapid X-ray variability. The high-quality, echellette…
We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements…
Observing programs comprising multiple scientific objectives will enhance the productivity of NASA's next UV/Visible mission. Studying active galactic nuclei (AGN) is intrinsically important for understanding how black holes accrete matter,…
Active Galactic Nuclei (AGNs) are characterized by emission of radiation over more than 10 orders of magnitude in frequency. Therefore, the execution of extensive surveys of the sky, with different types of detectors, is providing the…
The article summarizes the observational evidence for the existence of massive black holes, as well as the current knowledge about their abundance, their mass and spin distributions, and their cosmic evolution within and together with their…
Active Galactic Nuclei (AGN) can be probed by at different regions of the electromagnetic spectrum: e.g., radio observations reveal the nature of their relativistic jets and their magnetic fields, and complementarily, X-ray observations…
Astronomers have discovered many candidate black holes in X-ray binaries and in the nuclei of galaxies. The candidate objects are too massive to be neutron stars, and for this reason they are considered to be black holes. While the evidence…
Recent work revealed the existence of a galaxy "millimetre fundamental plane of black hole accretion", a tight correlation between nuclear $1$mm luminosity, intrinsic $2$ - $10$keV X-ray luminosity and supermassive black hole mass,…
Our understanding of the cosmic evolution of supermassive black holes (SMBHs) has been revolutionized by the advent of large multiwavelength extragalactic surveys, which have enabled detailed statistical studies of the host galaxies and…
Emission-line variability data for Seyfert 1 galaxies provide strong evidence for the existence of supermassive black holes in the nuclei of these galaxies, and that the line-emitting gas is moving in the gravitational potential of that…
We use a large, heterogeneous sample of local active galactic nuclei (AGN) that includes Seyfert 1s, Seyfert 2s and PG quasars to investigate for the first time the relation between black hole mass (M_BH) and mid-infrared nuclear emission.…
Black holes, an extreme consequence of the mathematics of General Relativity, have long been suspected of being the prime movers of quasars, which emit more energy than any other objects in the Universe. Recent evidence indicates that…
We present the first homogeneous sample of intermediate-mass black hole candidates in active galactic nuclei. Starting with broad-line active nuclei from the Sloan Digital Sky Survey, we use the linewidth-luminosity-mass scaling relation to…
Relativistic outflows are a common phenomenon in accreting black holes. Despite the enormous differences in scale, stellar-mass black holes in X-ray binaries and collapsars, and super-massive black holes at the dynamic centre of galaxies…