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Related papers: Spatially Offset Active Galactic Nuclei I: Selecti…

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Optical variability has proven to be an effective way of detecting AGNs in imaging surveys, lasting from weeks to years. In the present work we test its use as a tool to identify AGNs in the VST multi-epoch survey of the COSMOS field,…

We present medium resolution (R approx. 1500) ISO-SWS 2.4--45 micron spectra of a sample of 29 galaxies with active nuclei. This data set is rich in fine structure emission lines tracing the narrow line regions and (circum-)nuclear star…

Astrophysics · Physics 2009-11-07 E. Sturm , D. Lutz , A. Verma , H. Netzer , A. Sternberg , A. F. M. Moorwood , E. Oliva , R. Genzel

In this work we present the most comprehensive INTEGRAL AGN sample which lists 272 objects. Here we mainly use this sample to study the absorption properties of active galaxies, to probe new AGN classes and to test the AGN unification…

High Energy Astrophysical Phenomena · Physics 2015-06-05 A. Malizia , L. Bassani , A. Bazzano , A. J. Bird , N. Masetti , F. Panessa , J. B. Stephen , P. Ubertini

We present an X-ray analysis of fourteen nearby (z < 0.044) AGN in low mass galaxies (M_* <= 5*10^9 Msun) selected based on their optical variability (Baldassare et al. 2020). Comparing and contrasting different AGN selection techniques in…

Astrophysics of Galaxies · Physics 2023-08-09 Alexander Messick , Vivienne Baldassare , Marla Geha , Jenny Greene

The physical parameters of galaxies and/or AGNs can be derived by fitting their multi-band spectral energy distributions (SEDs). By using CIGALE code, we perform multi-band SED fitting (from ultraviolet to infrared) for 791 X-ray sources…

Astrophysics of Galaxies · Physics 2020-12-08 Xiaotong Guo , Qiusheng Gu , Nan Ding , E. Contini , Yongyun Chen

We employ the Chandra Multiwavelength Project (ChaMP) and the Sloan Digital Sky Survey (SDSS) to study the fraction of X-ray-active galaxies in the field out to z = 0.7. We utilize spectroscopic redshifts from SDSS and ChaMP, as well as…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Daryl Haggard , Paul J. Green , Scott F. Anderson , Anca Constantin , Tom L. Aldcroft , Dong-Woo Kim , Wayne A. Barkhouse

We report a new sample of obscured active galactic nuclei (AGNs) selected from the XMM serendipitous source and AKARI point-source catalogs. We match X-ray sources with infrared (18 and 90 micron) sources located at |b|>10 deg to create a…

Astrophysics of Galaxies · Physics 2015-11-18 Yuichi Terashima , Yoshitaka Hirata , Hisamitsu Awaki , Shinki Oyabu , Poshak Gandhi , Yoshiki Toba , Hideo Matsuhara

The ROSAT ALL Sky Survey Bright Source Catalogue (RASS-BSC) has been correlated with the Catalogue of Principal Galaxies (PGC) to identify new extragalactic counterparts. 550 reliable optical counterparts have been detected. We took optical…

Astrophysics · Physics 2009-11-13 W. Kollatschny , R. Kotulla , W. Pietsch , K. Bischoff , M. Zetzl

We are searching for large-scale structures in the distribution of AGN discovered by the ROSAT All-Sky Survey. The RASS detected > 60000 X-ray objects, of which approximately 35% are AGN at z < 0.5. The surface density in the extragalactic…

Astrophysics · Physics 2007-05-23 D. Engels , F. Tesch , C. Ledoux , J. Wei , A. Ugryumov , D. Valls-Gabaud , J. Hu , W. Voges

We test the merger-induced dual active galactic nuclei (dAGN) paradigm using a sample of 35 radio galaxy pairs from the SDSS Stripe 82 field. Using Keck optical spectroscopy, we confirm 21 pairs have consistent redshifts, constituting…

Astrophysics of Galaxies · Physics 2023-03-15 Arran C. Gross , Hai Fu , Adam D. Myers , Stanislav G. Djorgovski , Joshua L. Steffen , Joan M. Wrobel

We develop a novel method to identify active galactic nuclei (AGNs) and study the nature of low-luminosity AGNs in the Sloan Digital Sky Survey. This is the second part of a series of papers and we study the correlations between the AGN…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Masayuki Tanaka

We construct a new sample of 32 obscured active galactic nuclei (AGNs) selected from the Second XMM-Newton Serendipitous Source Catalogue to investigate their multiwavelength properties in relation to the "scattering fraction", the ratio of…

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

Hard X-ray surveys are an important tool for the study of active galactic nuclei (AGN): they provide almost an unbiased view of absorption in the extragalactic population, allow the study of spectral features such as reflection and high…

High Energy Astrophysical Phenomena · Physics 2013-02-12 Loredana Bassani , M. Molina , A. Malizia , F. Panessa , R. Landi , A. Bazzano , P. Ubertini , A. J. Bird , J. B. Stephen

The application of artificial neural networks (ANNs) for the estimation of HI gas mass fraction (\fgas) is investigated, based on a sample of 13,674 galaxies in the Sloan Digital Sky Survey (SDSS) with HI detections or upper limits from the…

Astrophysics of Galaxies · Physics 2016-12-07 Hossen Teimoorinia , Sara L. Ellison , David R. Patton

We report on the determination of electron densities, and their impact on the outflow masses and rates, measured in the central few hundred parsecs of 11 local luminous active galaxies. We show that the peak of the integrated line emission…

By providing homogeneous photometric and spectroscopic data of high quality for very large and objectively selected samples of galaxies, the Sloan Digital Sky Survey allows statistical studies of the physical properties of galaxies and AGN…

We investigate the link between optical obscuration and X-ray absorption in active galactic nuclei (AGN) by combining X-ray spectroscopy from 4XMM-DR11 with SDSS DR16Q spectroscopy. Bayesian X-ray spectral fits were obtained within the…

Astrophysics of Galaxies · Physics 2026-04-22 G. Mountrichas , F. J. Carrera , E. Quintin , A. Viitanen , A. Corral , N. Webb

(Abridged) We present an unbiassed near-IR selected AGN sample, covering 12.56 square degrees down to K ~ 15.5, selected from the Two Micron All Sky Survey (2MASS). Our only selection effect is a moderate color cut (J-K>1.2) designed to…

Astrophysics · Physics 2009-11-10 Paul J Francis , Brant O. Nelson , Roc M. Cutri

Context. A defining characteristic of active galactic nuclei (AGN) that distinguishes them from other astronomical sources is their stochastic variability, which is observable across the entire electromagnetic spectrum. Upcoming optical…

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