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Related papers: Spectral Energy Distribution profiles from AGN acc…

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Spectral energy distributions (SEDs) from X-ray to far-infrared (FIR) wavelengths are presented for a sample of 1246 X-ray luminous active galactic nuclei (AGN; $L_{0.5-10\rm{keV}}>10^{43}$ erg s$^{-1}$), with $z_{\rm{spec}}<1.2$, selected…

The structure of accretion flows in low-luminosity active galactic nuclei (AGN) at low Eddington ratios (~10^-2 to 10^-3) are poorly-understood, and can be probed using the spectral energy distributions (SEDs) of faded changing-look (CL)…

We have calculated the relativistic reflection component of the X-ray spectra of accretion disks in active galactic nuclei (AGN). Our calculations have shown that the spectra can be significantly modified by the motion of the accretion flow…

High Energy Astrophysical Phenomena · Physics 2009-11-13 Khee-Gan Lee , Kinwah Wu , Steven V. Fuerst , Graziella Branduardi-Raymont , Oliver Crowley

The local Seyfert 1.5 active galactic nucleus (AGN), NGC 6814, is known to exhibit complex variability, eclipses, and even changing-look behaviour. In this work, we utilize optical-to-X-ray data obtained over 10-years with the Neil Gehrels…

High Energy Astrophysical Phenomena · Physics 2025-06-10 L. K. Pothier-Bogoslowski , L. C. Gallo , A. G. Gonzalez , M. Z. Buhariwalla , J. M. Miller

X-ray spectroscopy offers an opportunity to study the complex mixture of emitting and absorbing components in the circumnuclear regions of active galactic nuclei, and to learn about the accretion process that fuels AGN and the feedback of…

High Energy Astrophysical Phenomena · Physics 2009-11-13 T. J. Turner , L. Miller

The nature of the broad-band spectra of supermassive accreting black holes in active galactic nuclei (AGNs) is still unknown. The hard X-ray spectra of Seyferts as well as of Galactic stellar-mass black holes (GBHs) are well represented by…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Alexandra Veledina , Indrek Vurm , Juri Poutanen

The presence of the warm absorber of considerable optical depth is seen in many AGN. We show that this medium may affect significantly the optical/UV spectrum of an AGN by backscattering a fraction of the total radiation flux towards the…

Astrophysics · Physics 2009-11-10 Z. Loska , B. Czerny , R. Szczerba

The UV-X continuum, the X-ray spectral features, and the variability in these bands provide powerful tools for studying the innermost regions of AGNs from which we gain an insight into the accretion process. In this chapter the discussion…

Astrophysics · Physics 2016-11-03 Suzy Collin

We study the broad-band spectral energy distribution (SED) of the prototypical low-mass active galactic nucleus (AGN) in NGC 4395. We jointly model the optical through mid-infrared SED with a combination of galaxy and AGN light, and find…

Astrophysics of Galaxies · Physics 2023-07-31 Hector Afonso G. Cruz , Andy D. Goulding , Jenny E. Greene

A wide-frequency radio study of Active Galactic Nuclei (AGN) is crucial to evaluate the intervening radiative mechanisms responsible for the observed emission and relate them with the underlying accretion physics. We present wide frequency…

One of the remaining open issues in the context of the analysis of Active Galactic Nuclei (AGN) is the evidence that nuclear gravitational accretion is often accompanied by a concurrent starburst (SB) activity. What is, in this picture, the…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-22 Anna Feltre

The standard alpha-disc model predicts an anti-correlation between the density of the inner accretion disc and the black hole mass times square of the accretion rate, as seen in higher mass ($M_{\rm BH}>10^{6} M_{\odot}$) active galactic…

The properties of slim accretion disks, while crucial for our understanding of black hole growth, have yet to be studied extensively observationally. We analyze the multi-epoch broad-band spectral energy distribution of the changing-look…

High Energy Astrophysical Phenomena · Physics 2024-09-17 Ruancun Li , Luis C. Ho , Claudio Ricci , Benny Trakhtenbrot

The "Cosmic Evolution Survey" (COSMOS) enables the study of the Spectral Energy Distributions (SEDs) of Active Galactic Nuclei (AGN) because of the deep coverage and rich sampling of frequencies from X-ray to radio. Here we present a SED…

Low-luminosity active galactic nuclei (LLAGNs) represent the bulk of the AGN population in the present-day universe and they trace the low-level accreting supermassive black holes. In order to probe the accretion and jet physical properties…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-21 Rodrigo Nemmen , Thaisa Storchi-Bergmann , Michael Eracleous

The accretion flow in AGN is not well understood, motivating intensive monitoring campaigns of multiwavelength variability to probe its structure. One of the best of these is the 3 year optical/UV/X-ray approximately daily monitoring…

High Energy Astrophysical Phenomena · Physics 2025-11-05 Scott Hagen , Chris Done , Edward M. Cackett , Ethan R. Partington , Rick Edelson , Collin Lewin , Erin Kara , Jonathan Gelbord

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…

Stars and compact objects embedded in accretion disks of active galactic nuclei (AGNs), dubbed as ``accretion-modified star" (AMS), often experience hyper-Eddington accretion in the dense gas environment, resulting in powerful outflows as…

High Energy Astrophysical Phenomena · Physics 2024-06-25 Jun-Rong Liu , Yi-Lin Wang , Jian-Min Wang

The observed evolution of the broad-band spectral energy distribution (SED) in NS X-ray Nova Aql X-1 during the rise phase of a bright FRED-type outburst in 2013 can be understood in the framework of thermal emission from unstationary…

We present spectral energy distributions (SEDs) of 41 active galactic nuclei, derived from multiwavelength photometry and archival spectroscopy. All of the SEDs span at least 0.09 to 30 micron, but in some instances wavelength coverage…

Astrophysics of Galaxies · Physics 2019-09-25 M. J. I. Brown , K. J. Duncan , H. Landt , M. Kirk , C. Ricci , N. Kamraj , M. Salvato , T. Ananna