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The magnitude-limited catalog of the Southern Sky Redshift Survey (SSRS2), is used to characterize the properties of galaxies hosting Active Galactic Nuclei. Using emission-line ratios, we identify a total of 162 (3%) Seyfert galaxies out…

Astrophysics · Physics 2009-11-10 Marcio A. G. Maia , Rodolfo S. Machado , Christopher N. A. Willmer

A sample of 37 nearby galaxies displaying composite LINER/HII and pure HII spectra was observed with the VLA in an investigation of the nature of their weak radio emission. The resulting radio contour maps overlaid on optical galaxy images…

Astrophysics · Physics 2009-10-31 Mercedes E. Filho , Peter D. Barthel , Luis C. Ho

We study the morphological and structural properties of the host galaxies associated with 57 optically-selected luminous type 2 AGN at $z\sim$0.3-0.4: 16 high-luminosity Seyfert 2 (HLSy2, 8.0$\le$log($L_{\rm [OIII]}/L_{\odot})<$8.3) and 41…

We report R~3000 VLT ISAAC K-band spectroscopy of the nuclei (i.e. central 100-300pc) of 9 galaxies hosting an active galactic nucleus. For 5 of these we also present spectra of the circumnuclear region out to 1kpc. We have measured a…

Astrophysics · Physics 2009-11-13 R. I. Davies , A. Sternberg , M. D. Lehnert , L. E. Tacconi-Garman

We used random forest algorithms to classify all objects in a large portion of the sky, using optical light curves obtained, or built from images provided, by the Zwicky Transient Facility (ZTF). We compare different selection sets based on…

Astrophysics of Galaxies · Physics 2025-03-25 S. Bernal , P. Sánchez-Sáez , P. Arévalo , F. E. Bauer , P. Lira , B. Sotomayor

We present the results of a campaign of simultaneous X-ray and optical observations of `true' Type 2 Seyfert galaxies candidates, i.e. AGN without a Broad Line Region (BLR). Out of the initial sample composed by 8 sources, one object,…

We present preliminary results of the analysis of optical spectra of two complementary samples of Seyfert galaxies. The first sample was extracted from a selection of the 4th Fermi Gamma-ray Large Area Telescope (4FGL) catalog, and consists…

Astrophysics of Galaxies · Physics 2023-11-06 Benedetta Dalla Barba , Marco Berton , Luigi Foschini , Giovanni La Mura , Amelia Vietri , Stefano Ciroi

We analyse 77 \textit{Fermi} sources and their potential low-energy counterparts previously proposed in the literature. These sources were classified as active galactic nuclei, mainly blazars, based on optical spectroscopy. The main goals…

High Energy Astrophysical Phenomena · Physics 2025-09-03 Alberto Ulgiati , Paolo Padovani , Paolo Giommi , Simona Paiano , Ciro Pinto

We present the largest currently existing subarcsecond 3-5 $\mu$m atlas of 119 local ($z < 0.3$) active galactic nuclei (AGN). This atlas includes AGN of 5 subtypes: 22 are Seyfert 1; 5 are intermediate Seyferts; 46 are Seyfert 2; 26 are…

The revision of the fourth Fermi Large Area Telescope (LAT) catalog of gamma-ray point sources (rev4FGL) revealed that the gamma-ray sky is populated by emerging populations of jetted active galactic nuclei (AGN) other than blazars and…

High Energy Astrophysical Phenomena · Physics 2026-01-27 Luigi Foschini

We present a sample of twenty-one ROSAT bright active galactic nuclei (AGN), representing a range of spectral classes, and selected for follow-up snap-shot observations with XMM-Newton. The typical exposure was between 5-10 ks. The objects…

Astrophysics · Physics 2009-11-13 L. C. Gallo , I. Lehmann , W. Pietsch , Th. Boller , W. Brinkmann , P. Friedrich , D. Grupe

We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT). Our aim is to prepare a list of jetted AGN with known redshifts and…

High Energy Astrophysical Phenomena · Physics 2021-10-06 L. Foschini , M. L. Lister , S. Antón , M. Berton , S. Ciroi , M. J. M. Marchã , M. Tornikoski , E. Järvelä , P. Romano , S. Vercellone , E. Dalla Bontà

The Spitzer high resolution spectra of 72 Seyfert galaxies from the 12$\mu$m Galaxy Sample are presented and discussed. The presence of starburst components in these galaxies can be quantified by powerful mid-IR diagnostics tools (i.e.…

Astrophysics · Physics 2008-07-31 S. Tommasin , L. Spinoglio , K. Hainline , M. A. Malkan , H. Smith

We present the results of a program of optical and near-infrared spectroscopic follow-up of candidate Active Galactic Nuclei (AGN) selected in the mid-infrared. This survey selects both normal and obscured AGN closely matched in luminosity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 M. Lacy , S. E. Ridgway , E. L. Gates , D. M. Nielsen , A. O. Petric , A. Sajina , T. Urrutia , S. Cox Drews , C. Harrison , N. Seymour , L. J. Storrie-Lombardi

Results are presented of extended and refined optical identification of 181 radio/X-ray sources in the RASS-Green Bank (RGB) catalog which have been spectroscopically observed in the Sloan digital sky survey (SDSS) DR5. For 72 sources, the…

High Energy Astrophysical Phenomena · Physics 2009-09-24 Deliang Wang , Jianguo Wang , Xiaobo Dong

The concept of the evolutionary sequence of jetted active galactic nuclei (AGNs) has been challenged in the last few decades since AGN subclasses are considered to be different due to their viewing angle. In this paper, we collected a…

Astrophysics of Galaxies · Physics 2022-01-26 Evaristus U. Iyida , Christian I. Eze , Finbarr C. Odo

Inspired by our serendipitous discovery of six AGNs with varying broad-Halpha fluxes over years out of our searching for intermediate-mass black holes (IMBHs), we conduct a systematic investigation of changing-look (CL) and…

Astrophysics of Galaxies · Physics 2021-07-08 Wen-Juan Liu , Paulina Lira , Su Yao , Dawei Xu , Jing Wang , Xiao-Bo Dong , Jorge Martínez-Palomera

We present optical spectroscopic observations of 93 galaxies taken from the infra-red selected COLA (Compact Objects in Low Power AGN) sample. The sample spans the range of far-IR luminosities from normal galaxies to LIRGs. Of the galaxies…

Active galactic nuclei (AGNs) are the compact, energetic central regions of galaxies, powered by supermassive black holes that accrete surrounding gas and dust. Their optical spectra can be identified by strong emission-line signatures…

Astrophysics of Galaxies · Physics 2026-01-09 Sruthi Suresh , Wei Jeat Hon , Rachel L Webster , Christian Wolf , Christopher A Onken
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