Related papers: Multi-frequency databases for AGN investigation - …
"Changing-look" active galactic nuclei (CL-AGNs) challenge our basic ideas about the physics of accretion flows and circumnuclear gas around supermassive black holes. Using first-year Sloan Digital Sky Survey V (SDSS-V) repeated…
Jetted Active Galactic Nuclei (AGN) hosting extended photoionized nebulae provide us with a unique view of the timescales associated with AGN activity. Here, we present a new Green Bean galaxy (RGB1) at $z=0.304458\pm0.000007$ with large…
We study the properties of 975 active galactic nuclei (AGN) selected by variability in the Pan-STARRS1 Medium-Deep Survey. Using complementary multi wavelength data from the ultraviolet to the far-infrared, we use SED fitting to determine…
The abundance of active galactic nuclei (AGN) in cosmic voids is relatively unexplored in the literature, but can potentially provide new constraints on the environmental dependence of AGN activity and the AGN-host co-evolution. We…
The Spitzer Space Telescope revolutionized studies of Active Galactic Nuclei (AGNs). Its combined sensitivity and mapping speed at mid-infrared wavelengths revealed a substantial population of highly-obscured AGNs. This population implies a…
We measure the correlation between sky coordinates of the Swift BAT catalogue of active galactic nuclei with the arrival directions of the highest energy cosmic rays detected by the Auger Observatory. The statistically complete, hard X-ray…
We describe improved modelling of the emission by dust in a toroidal--like structure heated by a central illuminating source within Active Galactic Nuclei (AGN). We chose a simple but realistic torus geometry, a flared disc, and a dust…
While observations in the radio band are providing essential information on the innermost structures of relativistic jets in active galactic nuclei (AGN), the recent detection by Fermi of gamma-ray emission from many hundreds of blazars…
Multi-frequency observations are a powerful tool of astrophysical investigation. Not only is data in each wavelength band providing different clues to the objects nature, but taken simultaneously, these data can reveal the mechanisms at…
The paradigm for AGN unification is reviewed, in terms of its optical manifestation as obscuration in the equatorial plane and its radio manifestation as relativistic beaming of the jet emission. Within this paradigm, observed AGN…
Merger-remnant galaxies with kpc-scale separation dual active galactic nuclei (AGNs) should be widespread as a consequence of galaxy mergers and triggered gas accretion onto supermassive black holes, yet very few dual AGNs have been…
We present medium resolution (R approx. 1500) ISO-SWS 2.4--45 micron spectra of a sample of 29 galaxies with active nuclei. This data set is rich in fine structure emission lines tracing the narrow line regions and (circum-)nuclear star…
We present the general properties of the Active Galactic Nuclei (AGNs) and discuss the origin and structure of jets that are associated to a fraction of these objects. We then we address the problems of particle acceleration at highly…
Active Galactic Nuclei (AGN) are generally considered as the scaled-up counterparts of X-ray binaries (XRBs). It is known that the power spectral density (PSD) of the X-ray emission of XRBs shows significant evolution with spectral states.…
We present the observed fraction of galaxies with an Active Galactic Nucleus (AGN) as a function of environment in the Early Data Release of the Sloan Digital Sky Survey (SDSS). Using 4921 galaxies between 0.05 <= z <= 0.095, and brighter…
This whitepaper describes how the VLASS could be designed in a manner to allow the identification of candidate dual active galactic nuclei (AGN) at separations <7 kpc. Dual AGN represent a clear marker of two supermassive black holes within…
Present AGN models aiming to account for the observed infrared SEDs consider a physical description of the dust and a solution of the radiative transfer problem. Mid infrared spectra obtained at different spatial scales are presented. They…
Among all the astronomical sources investigated through the prism of polarimetry, active galactic nuclei (AGN) have proven to be the richest in terms of complex yet fundamental signatures that helped to understand their true nature. Indeed,…
I briefly describe a few important scientific issues that could be addressed effectively via the combination of data from JDEM and X-ray missions. The topics covered are largely focused on active galactic nuclei (AGN) and include (1) the…
X-rays provide a robust method in identifying AGN. However, in the high-redshift Universe, their space density is relatively low, and, in combination with the small areas covered by X-ray surveys, the selected AGN are poorly sampled. Deep…