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Related papers: Naked active galactic nuclei

200 papers

We present Subaru/FOCAS spectropolarimetry of two active galaxies in the Cosmic Evolution Survey. These objects were selected to be optically dull, with the bright X-ray emission of an AGN but missing optical emission lines in our previous…

We show that the recently observed suppression of the gap between the broad line region (BLR) and the narrow line region (NLR) in some AGN can be fully explained by an increase of the gas density in the emitting region. Our model predicts…

Astrophysics of Galaxies · Physics 2016-11-17 T. P. Adhikari , A. Różańska , B. Czerny , K. Hryniewicz , G. J. Ferland

We present the analysis of the emission line galaxies members of 46 low redshift (0.04 < z < 0.07) clusters observed by WINGS (WIde-field Nearby Galaxy cluster Survey, Fasano et al. 2006). Emission line galaxies were identified following…

Astrophysics of Galaxies · Physics 2017-03-15 P. Marziani , M. D'Onofrio , D. Bettoni , B. M. Poggianti , A. Moretti , G. Fasano , J. Fritz , A. Cava , J. Varela , A. Omizzolo

We investigate why half of X-ray--selected active galactic nuclei (AGN) in deep surveys lack signs of accretion in their optical spectra. The majority of these ``optically--dull'' AGN are no more than 6 times fainter than their host…

Astrophysics · Physics 2011-07-18 J. R. Rigby , G. H. Rieke , J. L. Donley , A. Alonso-Herrero , P. G. Pérez-González

In order to characterize the amount of recent or ongoing stellar formation in the circumnuclear region of active galaxies on a statistically sound basis, we have studied the stellar component of the nuclear spectra in three different…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 P. Rafanelli , R. D'Abrusco , S. Ciroi , V. Cracco , F. Di Mille , L. Vaona

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

The detection of high-energy neutrinos from NGC 1068 and TXS-0506+56 suggests that active galactic nuclei (AGN) may contribute significantly to the the diffuse neutrino flux measured by IceCube. Using 10 years of publicly available IceCube…

High Energy Astrophysical Phenomena · Physics 2026-02-03 Samyak Jain , Dan Hooper , Francis Halzen

Accretion states, which are universally observed in stellar-mass black holes in X-ray binaries, are also anticipated in active galactic nuclei (AGN). This is the case at low luminosities, when the jet-corona coupling dominates the energy…

High Energy Astrophysical Phenomena · Physics 2021-04-28 Juan A. Fernández-Ontiveros , Teo Muñoz-Darias

Utilizing Chandra X-ray observations in the All-wavelength Extended Groth Strip International Survey (AEGIS) we identify 241 X-ray selected Active Galactic Nuclei (AGNs, L > 10^{42} ergs/s) and study the properties of their host galaxies in…

We present an imaging survey of the CO(1--0), HCN(1--0), and HCO$^+$(1--0) lines in the nearby Seyfert galaxies using the Nobeyama Millimeter Array and RAINBOW Interferometer. Some of the observed Seyfert galaxies including NGC 1068, NGC…

Astrophysics · Physics 2009-11-13 K. Kohno

We analyse the integral-field spectroscopy data for the $\approx10,000$ galaxies in final data release of the MaNGA survey. We identify 188 galaxies for which the emission lines cannot be described by single Gaussian components. These…

Astrophysics of Galaxies · Physics 2023-09-21 Youquan Fu , Michele Cappellari , Shude Mao , Shengdong Lu , Kai Zhu , Ran Li

We present mosaicked long-slit spectral maps of 18 nearby Active Galactic Nuclei (AGNs), 2 LINERs, and 4 star-forming galaxies. With the resulting data cubes taken using the Kast dual spectrograph on the 3 m Shane telescope of the Lick…

Astrophysics of Galaxies · Physics 2018-12-21 Junjie Xia , Matthew A. Malkan , Nathaniel R. Ross , Agnes J. Ancheta

We have discovered polarized broad emission lines in five type 2 Seyfert galaxies (NGC 424, NGC 591, NGC 2273, NGC 3081, and NGC 4507), establishing that these objects are type 1 Seyferts obscured by dense circumnuclear material. The…

Astrophysics · Physics 2009-10-31 E. C. Moran , A. J. Barth , L. E. Kay , A. V. Filippenko

We use mid-infrared spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space…

Astrophysics of Galaxies · Physics 2010-01-15 G. D. Thompson , N. A. Levenson , S. A. Uddin , M. M. Sirocky

We analyze ionized gas emission lines in deep rest-frame optical spectra of 16 quiescent galaxies at redshift $1.7<z<3.5$ observed with JWST/NIRSpec by the Blue Jay survey. Robust detection of emission lines in $75\%$ of the sample…

We report on candidate active galactic nuclei (AGN) discovered during the monitoring of $\sim$500 bright (r < 18 mag) galaxies over several years with the Kepler Mission. Most of the targets were sampled every 30 minutes nearly continuously…

High Energy Astrophysical Phenomena · Physics 2015-12-09 Edward J. Shaya , Robert Olling , Richard Mushotzky

The impact of Active Galactic Nuclei (AGN) on star formation has implications for our understanding of the relationships between supermassive black holes and their galaxies, as well as for the growth of galaxies over the history of the…

Astrophysics of Galaxies · Physics 2019-04-24 David J. Rosario , Aditya Togi , Leonard Burtscher , Ric Davies , Taro Shimizu , Dieter Lutz

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

We report the discovery of an active galactic nucleus (AGN) pair in the interacting galaxy system IRAS 20210+1121 at z = 0.056. An XMM-Newton observation reveals the presence of an obscured (Nh ~ 5 x 10^{23} cm^-2), Seyfert-like (L_{2-10…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 E. Piconcelli , C. Vignali , S. Bianchi , S. Mathur , F. Fiore , M. Guainazzi , G. Lanzuisi , R. Maiolino , F. Nicastro

Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broad-line (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type…