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Related papers: Machine learning applications for the study of AGN…

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In this paper we discuss an application of machine learning based methods to the identification of candidate AGN from optical survey data and to the automatic classification of AGNs in broad classes. We applied four different machine…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-14 Stefano Cavuoti , Massimo Brescia , Raffaele D'Abrusco , Giuseppe Longo , Maurizio Paolillo

We use observations from the 9 square degree multiwavelength survey in Bootes to identify hundreds of obscured active galactic nuclei (AGN) with high redshifts (z > 0.7), luminosities (L_bol > 10^45 ergs/s), and moderate obscuring columns…

Active Galactic Nuclei (AGN) are powered by the accretion of material onto a supermassive black hole (SMBH), and are among the most luminous objects in the Universe. However, the huge radiative power of most AGN cannot be seen directly, as…

Astrophysics of Galaxies · Physics 2018-10-17 Ryan C. Hickox , David M. Alexander

(abridged)Photometric redshifts for AGN (galaxies hosting an accreting supermassive black hole in their center) are notoriously challenging and currently better computed via SED fitting, assuming that deep photometry for many wavelengths is…

We have determined the cosmological evolution of the density of AGN and of their Nh distribution as a function of the un-absorbed 2-10 keV luminosity up to redshift 4. We used the HELLAS2XMM sample combined with other published catalogs,…

We present a study of the 1173 sources brighter than $S_{1.4\,\rm GHz}= 120\,\mu$Jy detected over an area of $\simeq 1.4\,\hbox{deg}^{2}$ in the Lockman Hole field. Exploiting the multi-band information available in this field for $\sim$79%…

Astrophysics of Galaxies · Physics 2020-12-08 Matteo Bonato , Isabella Prandoni , Gianfranco De Zotti , Marisa Brienza , Raffaella Morganti , Mattia Vaccari

We present a census of local active galactic nuclei (AGN) at a redshift of $z\leq0.025$ selected using the high-ionization [Ne v] $\lambda14.32\,\mu$m emission line from the Infrared Database of Extragalactic Observables from Spitzer…

Astrophysics of Galaxies · Physics 2026-03-16 S. Yassir , A. Annuar

We study the relation between obscuration and supermassive black hole (SMBH) growth using a large sample of hard X-ray selected Active Galactic Nuclei (AGN). We find a strong decrease in the fraction of obscured sources above the Eddington…

The outshining light from active galactic nuclei (AGNs) poses significant challenges in studying the properties of AGN host galaxies. To address this issue, we propose a novel approach which combines image decomposition and spectral energy…

Astrophysics of Galaxies · Physics 2025-02-11 Haoran Yu , Lulu Fan , Yunkun Han , Weibin Sun , Yihang Zhang , Xuheng Ding , Yongquan Xue

We have conducted a systematic search of low-mass black holes (BHs) in active galactic nuclei (AGNs) with broad Halpha emission lines, aiming at building a homogeneous sample that is more complete than previous ones for fainter, less highly…

Astrophysics of Galaxies · Physics 2015-06-05 Xiao-Bo Dong , Luis C. Ho , Weimin Yuan , Ting-Gui Wang , Xiaohui Fan , Hongyan Zhou , Ning Jiang

A new sample of 204 low-mass black holes (LMBHs) in active galactic nuclei (AGNs) is presented with black hole masses in the range of (1-20) * 10^5 M_sun. The AGNs are selected from a systematic search among galaxies in the Seventh Data…

Astrophysics of Galaxies · Physics 2018-05-04 He-Yang Liu , Weimin Yuan , Xiao-Bo Dong , Hongyan Zhou , Wen-Juan Liu

Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Stefano Bianchi , Vincenzo Mainieri , Paolo Padovani

Computing photo-z for AGN is challenging, primarily due to the interplay of relative emissions associated with the SMBH and its host galaxy. SED fitting methods, effective in pencil-beam surveys, face limitations in all-sky surveys with…

Active Galactic Nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique observational signatures that cover the full electromagnetic spectrum over more than twenty…

We present two catalogues of active galactic nucleus (AGN) candidates selected from the latest data of two all-sky surveys -- Data Release 2 (DR2) of the \emph{Gaia} mission and the unWISE catalogue of the \emph{Wide-field Infrared Survey…

Context: Finding Active Galactic Nuclei (AGN) behind the Magellanic Clouds (MCs) is difficult because of the high stellar density in these fields. Although the first AGN behind the Small Magellanic Cloud (SMC) were reported in the 1980s, it…

High Energy Astrophysical Phenomena · Physics 2019-01-30 C. Maitra , F. Haberl , V. D. Ivanov , Maria-Rosa L. Cioni , Jacco Th. van Loon

The masses and emission-line region sizes of Active Galactic Nuclei (AGNs) can be measured by ``reverberation-mapping'' (measuring the lag of the emission-line luminosity after changes in the continuum). We use tis technique to calibrate…

Astrophysics · Physics 2008-11-26 A. Wandel , B. M. Peterson , M. A. Malkan

The study of heavily obscured supermassive black hole (SMBH) growth in late-stage galaxy mergers is challenging: column densities $N_{\mathrm{H}}>10^{24},\mathrm{cm}^{-2}$ can block most nuclear emission, leaving significant gaps in the…

Despite the increasing number of Gravitational Wave (GW) detections, the astrophysical origin of Binary Black Hole (BBH) mergers remains elusive. A promising formation channel for BBHs is inside accretion discs around supermassive black…

High Energy Astrophysical Phenomena · Physics 2023-10-25 Niccolò Veronesi , Elena Maria Rossi , Sjoert van Velzen

We present a census of the active black hole population at 1<z<2, by constructing the bivariate distribution function of black hole mass and Eddington ratio, employing a maximum likelihood fitting technique. The study of the active black…