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Related papers: Blue, Green, and Red Bumps in AGN

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Theory and observations of the dominant thermal continuum emission in AGNs are examined. After correction for reddening, the steady state AGN optical--UV spectral energy distributions (SEDs) are very similar. The SEDs are dominated…

Astrophysics · Physics 2007-11-15 C. Martin Gaskell

Spectral Energy Distribution (SED) of the broad-band continuum emission from black-hole accretion discs can serve as a tool to measure parameters of the central body and constrain the geometry of the inner accretion flow. We focus on the…

High Energy Astrophysical Phenomena · Physics 2023-06-21 Marcel Štolc , Michal Zajaček , Bożena Czerny , Vladimír Karas

The broadband spectral energy distribution (SED) of Active Galactic Nuclei (AGN) is investigated for a well-selected sample composed of $23$ Seyfert 1 galaxies observed simultaneously in the optical/UV and X-ray bands with the Neil Gehrels…

High Energy Astrophysical Phenomena · Physics 2019-06-12 Huaqing Cheng , Weimin Yuan , He-Yang Liu , A. A. Breeveld , Chichuan Jin , Bifang Liu

We present and analyse quasi-simultaneous multi-epoch spectral energy distributions (SEDs) of seven reverberation-mapped AGNs for which accurate black hole mass measurements and suitable archival data are available from the 'AGN Watch'…

Astrophysics of Galaxies · Physics 2017-12-27 Ece Kilerci-Eser , Marianne Vestergaard

We reexamine the hypothesis that the optical/UV/soft X-ray continuum of Active Galactic Nuclei is thermal emission from an accretion disk. Previous studies have shown that fitting the spectra with the standard, optically thick and…

Astrophysics · Physics 2009-10-28 Ewa Szuszkiewicz , Matthew A. Malkan , Marek A. Abramowicz

The inner structure of AGNs is expected to change below a certain luminosity limit. The big blue bump, footprint of the accretion disk, is absent for the majority of low-luminosity AGNs (LLAGNs). Moreover, recent simulations suggest that…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 J. A. Fernández-Ontiveros , M. A. Prieto , J. A. Acosta-Pulido , M. Montes

A recent study on the spectral energy distribution (SED) of AGN combined unobscured X-ray sources from the eROSITA eFEDS Survey with high quality optical imaging from Subaru's Hyper Suprime-Cam (HSC). The HSC data enabled accurate host…

High Energy Astrophysical Phenomena · Physics 2025-01-23 Jia-Lai Kang , Chris Done , Scott Hagen , Matthew J. Temple , John D. Silverman , Junyao Li , Teng Liu

The physical origin of optical changing-look AGNs (CLAGNs), characterized by the appearance or disappearance of broad emission lines, is thought to be mainly driven by the variation of the black-hole (BH) accretion rate. In this work, we…

High Energy Astrophysical Phenomena · Physics 2026-04-15 Pengyuan Han , Huaiyuan Lu , Bing Lyu , Jiancheng Wu , Qingwen Wu

We propose a solution to the problem of accretion disc sizes in active galactic nuclei being larger when measured by reverberation mapping than predicted by theory. Considering blackbody reprocessing on a disc with thickness profile $H(r)$,…

Astrophysics of Galaxies · Physics 2022-12-28 D. A. Starkey , Jiamu Huang , Keith Horne , Douglas N. C. Lin

Understanding how active galactic nuclei (AGN) affect their host galaxies requires determining their total radiative power across all wavelengths (i.e., bolometric luminosities). We show how AGN accretion disk spectral energy distribution…

Astrophysics of Galaxies · Physics 2025-09-25 Mojegan Azadi , Belinda Wilkes , Joanna Kuraszkiewicz , Steven. P. Willner , Matthew L. N. Ashby

We perform spectral energy distribution (SED) fitting to 711 luminous X-ray AGN at 0.7 < z < 4.5 using 10-bands of optical and infra-red photometric data for objects within XMM-SERVS. This fitting provided 510 reliable (reduced $\chi ^2 <…

Astrophysics of Galaxies · Physics 2022-07-27 Adam Marshall , Matthew W. Auger-Williams , Manda Banerji , Roberto Maiolino , Rebecca Bowler

In this third paper in a series of three, we present a detailed study of the AGN broadband SED based on a nearby unobscured Type 1 AGN sample. We perform a systematic cross-correlation study of the following key parameters:…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Chichuan Jin , Martin Ward , Chris Done

We present a thorough study of the Changing-Look Active Galactic Nucleus (CL-AGN) Mrk 1018, utilizing an extensive dataset spanning optical, UV, and X-ray spectro-photometric data from 2005 to 2019. We analysed X-ray spectra and broad-band…

High Energy Astrophysical Phenomena · Physics 2023-12-14 S. Veronese , C. Vignali , P. Severgnini , G. A. Matzeu , M. Cignoni

We employ optical and UV observations to present SEDs for two reverberation-mapped samples of super-Eddington and sub-Eddington AGN with similar luminosity distributions. The samples are fitted with accretion disc models in order to look…

Astrophysics of Galaxies · Physics 2016-03-09 Nuria Castello-Mor , Hagai Netzer , Shai Kaspi

We explore the evolution with redshift of the rest-frame colours and space densities of AGN hosts (relative to normal galaxies) to shed light on the dominant mechanism that triggers accretion onto supermassive black holes as a function of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. Georgakakis , A. L. Coil , C. N. A. Willmer , K. Nandra , D. D. Kocevski , M. C. Cooper , D. J. Rosario , D. C. Koo , J. R. Trump , S. Juneau

We develop a new spectral model for the broadband spectral energy distribution (SED) of Active Galactic Nuclei (AGN). This includes an outer standard disc, an inner warm Comptonising region to produce the soft X-ray excess and a hot corona.…

High Energy Astrophysical Phenomena · Physics 2018-08-01 Aya Kubota , Chris Done

Modeling the spectral energy distribution (SED) of active galactic nuclei (AGN) plays a very important role in constraining modern cosmological simulations of galaxy formation. Here, we utilize an advanced supermassive black hole (SMBH)…

Astrophysics of Galaxies · Physics 2026-03-23 Tong Su , Qi Guo , Erlin Qiao , Wenxiang Pei , Luis C. Ho , Cedric G. Lacey

We present infrared (IR) to X-ray spectral energy distributions (SEDs) for 44 red AGN selected from the 2MASS survey on the basis of their red J-K$_S$ color (>2 mag) and later observed by Chandra. In comparison with optically-, radio-, and…

The characteristic timescale ($\tau$) of continuum variability of the accretion disk in active galactic nuclei (AGNs) is known to be related to the thermal timescale, which is predicted to scale with AGN luminosity ($L$) and restframe…

Astrophysics of Galaxies · Physics 2025-03-26 Suyeon Son , Minjin Kim , Luis C. Ho

The discovery of changing-look active galactic nuclei (CL AGNs), with appearance and disappearance of broad emission lines and/or with strong variation of line-of-sight column density within a few years, challenges the AGN unification…

Astrophysics of Galaxies · Physics 2019-12-10 Hao liu , Qingwen Wu , Bing Lyu , Zhen Yan
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