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Related papers: Testing the AGN Unification Model in the Infrared

200 papers

Over ten mid-infrared (mid-IR) and X-ray models are currently attempting to describe the nuclear obscuring material of active galactic nuclei (AGNs), but many questions remain unresolved. This study aims to determine the physical parameters…

Several authors have claimed that the less luminous active galactic nuclei (AGN) are not capable of sustaining the dusty torus structure. Thus, a gradual re-sizing of the torus is expected when the AGN luminosity decreases. Our aim is to…

We combine near-to-mid-IR Spitzer data with shorter wavelength observations (optical to X-rays) to get insights on the properties of a sample of luminous, obscured Active Galactic Nuclei (AGN). We aim at modeling their broad-band Spectral…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Pozzi , C. Vignali , A. Comastri , E. Bellocchi , J. Fritz , C. Gruppioni , M. Mignoli , R. Maiolino , L. Pozzetti , M. Brusa , F. Fiore , G. Zamorani

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

This article presents the first part of a study aimed at testing the unification paradigm for AGN (UPAGN) using the SED reconstruction code X-CIGALE. Our method consists in obtaining a generic SED for a large sample of Seyfert 1 (Sy1; part…

We present an optical variability analysis and comparison of the samples of Seyfert 1 and 2 galaxies, selected from the \textit{Swift} 9-month BAT catalog, using the light curves from Transiting Exoplanet Survey Satellite (TESS) and All-Sky…

One of the fundamental concepts in the unified scheme of AGN is that both Seyfert 1 and Seyfert 2 galaxies harbour supermassive nuclear engines blocked from direct view by an optically and geometrically thick torus. If the pressure is…

Astrophysics · Physics 2007-05-23 C. M. Violette Impellizzeri , Alan L. Roy , Christian Henkel

Context: We investigate mid-infrared and X-ray properties of the dusty torus invoked in the unification scenario for active galactic nuclei. Aims: We use the relation between mid IR and hard X-ray luminosities to constrain the geometry and…

Astrophysics · Physics 2009-11-13 Hannes Horst , Poshak Gandhi , Alain Smette , Wolfgang J. Duschl

Observations at ultraviolet, optical and near-infrared wavelengths have shown the existence of recent star formation in the nuclear regions of Seyfert 2 (Sy2) galaxies that suggest a connection between the Starburst and the Seyfert…

Astrophysics · Physics 2007-05-23 Rosa M. Gonzalez Delgado

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

The Unified Model of Active Galactic Nuclei (AGN) has provided a successful explanation for the observed diversity of AGN in the local Universe. However, recent analysis of multi-wavelength spectral and image data suggests that the Unified…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 M. J. Rutkowski , P. R. Hegel , Hwihyun Kim , Kazuyuki Tamura , R. A. Windhorst

Coronal-Line Forest Active Galactic Nuclei (CLiF AGN) are characterized by strong, high-ionization lines, which are in contrast to what is found in typical AGNs. Here, we carry out an infrared analysis aimed at understanding the spectral…

Astrophysics of Galaxies · Physics 2023-07-05 F. C. Cerqueira-Campos , A. Rodríguez-Ardila , S. Panda , R. Riffel , L. G. Dahmer-Hahn , M. Marinello

In Unification Models, Active Galactic Nuclei (AGN) are believed to be surrounded by an axisymmetric structure of dust and gas, which greatly influences their observed properties according to the direction from which they are observed. The…

Astrophysics · Physics 2009-11-11 E. Ibar , P. Lira

Despite the hypothesized similar face-on viewing angles, the infrared emission of type-1 AGNs has diverse spectral energy distribution (SED) shapes that deviate substantially from the well-characterized quasar templates. Motivated by the…

Astrophysics of Galaxies · Physics 2018-10-17 Jianwei Lyu , George H. Rieke

The Wide-field Infrared Survey Explorer (WISE) has scanned the entire sky with unprecedented sensitivity in four infrared bands, at 3.4, 4.6, 12, and 22 micron. The WISE Point Source Catalog contains more than 560 million objects, among…

Astrophysics of Galaxies · Physics 2015-06-18 Robert Nikutta , Maia Nenkova , Zeljko Ivezic , Nicholas Hunt-Walker , Moshe Elitzur

We present the results of a systematic, broadband X-ray spectral analysis of nearby active galactic nuclei (AGNs) with the X-ray clumpy torus model (XCLUMPY; Tanimoto et al. 2019). By adding 16 AGNs newly analyzed in this paper, we study…

High Energy Astrophysical Phenomena · Physics 2021-01-20 Shoji Ogawa , Yoshihiro Ueda , Atsushi Tanimoto , Satoshi Yamada

A cornerstone of AGN unification schemes is the presence of an optically and geometrically thick dust torus. It provides the obscuration to explain the difference between type 1 and type 2 AGN. We investigate the influence of the dust…

Astrophysics · Physics 2007-09-24 Sebastian F. Hoenig , Thomas Beckert

Aims: The unification scheme of Seyfert galaxies predicts that the observed differences between type 1 and type 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around AGN. The…

High Energy Astrophysical Phenomena · Physics 2015-03-17 Veeresh Singh , Prajval Shastri , Guido Risaliti

We have obtained high-resolution mid-infrared (MIR) imaging, nuclear spectral energy distributions (SEDs) and archival Spitzer spectra for 22 low-luminosity active galactic nuclei (LLAGN; L_bol < 5 x 10^42 erg/s). Infrared (IR) observations…

We present the results of X-ray spectral analysis of 22 active galactic nuclei (AGNs) with a small scattering fraction selected from the Second XMM-Newton Serendipitous Source Catalogue using hardness ratios. They are candidates of buried…

Astrophysics of Galaxies · Physics 2014-11-20 Kazuhisa Noguchi , Yuichi Terashima , Hisamitsu Awaki