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Related papers: Testing the AGN Paradigm, Part I: a generic SED fo…

200 papers

We analyze the emission properties of a new sample of 3,579 type 1 AGN, selected from the SDSS DR7 based on the detection of broad H-alpha emission. The sample extends over a broad H-alpha luminosity L_bHa of 10^40 - 10^44 erg s^-1 and a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jonathan Stern , Ari Laor

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 new frontiers in the modelling of the spectral energy distributions (SED) of active galaxies by introducing the radio-to-X-ray fitting capabilities of the publicly available Bayesian code AGNfitter. The new code release, called…

The range of currently proposed active galactic nucleus (AGN) far-infrared templates results in uncertainties in retrieving host galaxy information from infrared observations and also undermines constraints on the outer part of the AGN…

Astrophysics of Galaxies · Physics 2017-05-26 Jianwei Lyu , George H. Rieke

The infrared is a key wavelength regime for probing the dusty, obscured nuclear regions of active galaxies. We present results from an infrared study of 87 nearby Seyfert galaxies using the Spitzer Space Telescope and ground-based…

We present ongoing work on the spectral energy distributions (SEDs) of active galactic nuclei (AGNs), derived from X-ray, ultraviolet, optical, infrared and radio photometry and spectroscopy. Our work is motivated by new wide-field imaging…

Astrophysics of Galaxies · Physics 2020-06-17 M. J. I. Brown , K. J. Duncan , H. Landt , M. Kirk , C. Ricci , N. Kamraj

We summarize recent results on the infrared (IR) nuclear properties of Seyfert galaxies. 100% of all Seyfert 1-1.9$ and ~50% of all Seyfert 2s in the CfA and RSA samples observed with HST/NICMOS show nuclear point sources at 1.6micron. We…

Astrophysics · Physics 2007-05-23 Almudena Alonso-Herrero

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

Context: The unification scheme of Seyfert galaxies hypothesizes that Seyfert type 1s and type 2s are intrinsically similar and the observed differences between the two subtypes are solely due to the differing orientations of…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-19 Veeresh Singh , Prajval Shastri , Guido Risaliti

We present a series of statistical tests using homogeneous data and measurements for a sample of Seyfert galaxies. These galaxies were selected from mostly isotropic properties, their far infrared fluxes and warm infrared colors, which…

There is evidence for significant evolution in the gaseous and dust properties of galaxies since the era of cosmic noon ($1\lesssim z\lesssim 2.5$). The well known co-evolution of supermassive black holes with their host galaxies suggests a…

Astrophysics of Galaxies · Physics 2025-12-10 Devang H. Liya , David J. Rosario , Matthaios Charidis

Narrow Line Seyfert 1 galaxies represent a distinct category in the larger family of Type 1 Active Galactic Nuclei. The occurrence of emission line profiles not broader than 2000 km/s, combined with luminosity estimates comparable to those…

High Energy Astrophysical Phenomena · Physics 2011-06-14 G. La Mura , S. Ciroi , V. Cracco , D. Ilić , L. Č. Popović , P. Rafanelli

We present the results of a Suzaku monitoring campaign of the Seyfert 2 galaxy, NGC7582. The source is characterized by very rapid (on timescales even lower than a day) changes of the column density of an inner absorber, together with the…

Astrophysics of Galaxies · Physics 2011-02-11 Stefano Bianchi , Enrico Piconcelli , Marco Chiaberge , Elena Jimenez Bailon , Giorgio Matt , Fabrizio Fiore

We develop a new diagnostic method to classify galaxies into AGN hosts, star-forming galaxies, and absorption-dominated galaxies by combining the [O III]/Hbeta ratio with rest-frame U-B color. This can be used to robustly select AGNs in…

Two major challenges to unification schemes for active galactic nuclei (AGN) are the existence of Narrow-Line Seyfert 1s (NLS1s) and the existence of changing-look (CL) AGNs. AGNs can drastically change their spectral appearance in the…

Astrophysics of Galaxies · Physics 2019-07-09 Victor L. Oknyansky , Konstantin L. Malanchev , C. Martin Gaskell

We are conducting a large observing program with the Spitzer Space Telescope to determine the mid-to-far infrared spectral energy distributions of a well-defined sample of 87 nearby, 12 micron-selected Seyfert galaxies. In this paper we…

Using the CIGALE software, we present the preliminary results of a multiwavelength analysis of eighteen low-redshift isolated galaxies with active nuclei (isolated AGNs). This sample was formed by cross-matching the 2MIG isolated AGNs…

Astrophysics of Galaxies · Physics 2025-11-26 O. Kompaniiets

(Abbreviated) We assemble a sample composed of 243 nearby Seyfert galaxies with redshifts $z\le 0.05$ to test the unification scheme. The sample contains 94 BLS1s, 44 NLS1s, 36 X-ray absorbed HBLR S2s, 42 X-ray absorbed non-HBLR S2s and 27…

Astrophysics · Physics 2011-02-11 Jian-Min Wang , En-Peng Zhang

Obscuring circumnuclear dust is a well-established constituent of active galactic nuclei (AGN). Traditionally referred to as the receding dusty torus, its inner radius and angular extension should depend on the photo-ionizing luminosity of…

High Energy Astrophysical Phenomena · Physics 2016-06-15 F. Marin , R. W. Goosmann , P. -O. Petrucci

(abridged) This paper is the second part of a work investigating the properties of dusty tori in AGN by means of multi-component SED fitting. It focuses on low luminosity, low redshift (z < 0.25) AGN selected among emission line galaxies as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Evanthia Hatziminaoglou , Jacopo Fritz , Tom Jarrett
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