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Related papers: The viewing angle in AGN SED models, a data-driven…

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We report Swift observations of a sample of 92 bright soft X-ray selected active galactic nuclei (AGN). This sample represents the largest number of AGN observed to study the spectral energy distribution (SED) of AGN with simultaneous…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Dirk Grupe , S. Komossa , Karen M. Leighly , Kim L. Page

We study the host galaxy properties of active galactic nuclei (AGN) that have been detected in X-rays in the nearby Universe ($\rm z<0.2$). For that purpose, we use the catalogue provided by the ROSAT-2RXS in the 0.1-2.4\,keV energy band,…

Astrophysics of Galaxies · Physics 2022-02-02 L. Koutoulidis , G. Mountrichas , I. Georgantopoulos , E. Pouliasis , M. Plionis

Active Galactic Nuclei (AGN) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight, yet the specific inclinations of all but a few AGN are generally…

Astrophysics of Galaxies · Physics 2015-06-18 T. C. Fischer , D. M. Crenshaw , S. B. Kraemer , H. R. Schmitt , T. J. Turner

Estimating physical quantities such as the star formation rate, stellar mass and active galactic nucleus (AGN) fraction of galaxies is a key step in understanding galaxy formation and evolution. In order to estimate the uncertainties in the…

Astrophysics of Galaxies · Physics 2025-01-14 Michail Papadopoulos , Vicky Papadopoulou Lesta , Ioannis Michos , Duncan Farrah , Andreas Efstathiou

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…

Astrophysics of Galaxies · Physics 2025-05-21 E. Pouliasis , A. Ruiz , I. Georgantopoulos , A. Akylas , N. A. Webb , F. J. Carrera , S. Mateos , A. Nebot , M. G. Watson , F. X. Pineau , C. Motch

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…

Emission from active galactic nuclei (AGNs) is known to play an important role in the evolution of many galaxies including luminous and ultraluminous systems (U/LIRGs), as well as merging systems. However, the extent, duration, and exact…

We have employed a reliable technique of classification of Active Galactic Nuclei (AGN) based on the fit of well-sampled spectral energy distributions (SEDs) with a complete set of AGN and starburst galaxy templates. We have compiled…

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…

We classify the spectral energy distributions (SEDs) of 431,038 sources in the 9 sq. deg Bootes field of the NOAO Deep Wide-Field Survey (NDWFS). There are up to 17 bands of data available per source, including ultraviolet (GALEX), optical…

We present new mid-infrared (MIR) imaging data for three Type-1 Seyfert galaxies obtained with T-ReCS on the Gemini-South Telescope at subarcsecond resolution. Our aim is to enlarge the sample studied in a previous work to compare the…

We present results of recurrence analysis of 46 active galactic nuclei (AGN) using light curves from the 157-month catalog of the Swift Burst Alert Telescope (BAT) in the 14-150 keV band. We generate recurrence plots and compute recurrence…

High Energy Astrophysical Phenomena · Physics 2022-11-28 R. A. Phillipson , M. S. Vogeley , P. T. Boyd

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

The detection of X-ray emission constitutes a reliable and efficient tool for the selection of Active Galactic Nuclei (AGNs), although it may be biased against the most heavily absorbed AGNs. Simple mid-IR broad-band selection criteria…

Astrophysics of Galaxies · Physics 2020-05-06 E. Pouliasis , G. Mountrichas , I. Georgantopoulos , A. Ruiz , M. Yang , A. Z. Bonanos

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

Active Galactic Nuclei (AGN) have long been known to be variable, but the amplitude, timescale and nature of these changes can often differ dramatically from object to object. The richest source of information about the properties of AGN…

Astrophysics of Galaxies · Physics 2021-07-14 Hartmut Winkler

This study involves a comparative analysis of the SFRs of AGN and non-AGN galaxies and of the SFRs of type 1 and 2 AGN. To carry out this investigation, we assembled a dataset consisting of 2\,677 X-ray AGN detected by the XMM-Newton…

Astrophysics of Galaxies · Physics 2024-01-18 G. Mountrichas , V. A. Masoura , A. Corral , F. J. Carrera

Active galactic nuclei (AGN) are typically identified through radio, mid-infrared, or X-ray emission or through the presence of broad and/or narrow emission lines. AGN can also leave an imprint on a galaxy's spectral energy distribution…

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…

The INTEGRAL mission provides a large data set for studying the hard X-ray properties of AGN and allows to test the unified scheme for AGN. We present results based on the analysis of 199 AGN. A difference between the Seyfert types is…

High Energy Astrophysical Phenomena · Physics 2010-01-26 V. Beckmann , C. Ricci , S. Soldi , J. Alfonso-Garzon , T. J. -L. Courvoisier , A. Domingo , N. Gehrels , P. Lubinski , J. M. Mas-Hesse , A. A. Zdziarski