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Related papers: Spectropolarimetry of Compton-thin Seyfert 2s

200 papers

(abridged) With the commissioning of XMM came the discovery of 2.5-10 keV spectral complexity in some narrow-line Seyfert 1 galaxies (NLS1). In this work, we define two samples of NLS1: a complex sample whose members exhibit high-energy…

Astrophysics · Physics 2009-11-11 L. C. Gallo

The first X-ray observation of the Seyfert 2 galaxy NGC5252 is reported. ASCA collected $\sim 4000$ photons/detector enough to perform an accurate spectral analysis of this source. The luminosity of NGC5252 is L$_{\rm X}$(0.7-10 keV)…

Astrophysics · Physics 2009-10-28 M. cappi , T. Mihara , M. Matsuoka , W. Brinkmann , M. A. Prieto , G. G. C. Palumbo

Narrow-line Seyfert\,1 galaxies (NLS1s) with very small broad-line widths (say, FWHM(\hb) $\la $ 1200\,\kms) represent the extreme type of Seyfert\,1 galaxies that have small black hole masses (\mbh) and/or high Eddington ratios (\redd).…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Y. L. Ai , W. Yuan , H. Y. Zhou , T. G. Wang , S. H. Zhang

We measure spectral features of ~3500 K-selected galaxies at 0.5<z<2.0 from high quality medium-band photometry using a new technique. First, we divide the galaxy sample in 32 subsamples based on the similarities between the full spectral…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Mariska Kriek , Pieter G. van Dokkum , Katherine E. Whitaker , Ivo Labbe , Marijn Franx , Gabriel B. Brammer

Based on the analysis of a large spectropolarimetric survey of Seyfert 2 galaxies (S2s) from the CfA and 12-micron samples conducted mostly at Lick and Palomar Observatories, it is shown that S2s with hidden BLR (HBLRs) are intrinsically…

Astrophysics · Physics 2007-05-23 Hien D. Tran

The Unified Model of AGN predicts the sole difference between Seyfert 1 and Seyfert 2 nuclei is the viewing angle with respect to an obscuring structure around the nucleus. High energy photons above 20 keV are not affected by this…

Astrophysics · Physics 2015-05-13 Matthew Middleton , Chris Done , Nick Schurch

Aims: We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN), of all degrees of activity, in the wavelength interval of 0.8-2.4 microns, including the fluxes of the observed emission lines. We analyze the spectroscopic…

Astrophysics · Physics 2009-11-11 R. Riffel , A. Rodriguez-Ardila , M. G. Pastoriza

An optical spectropolarimetric study has shown that the detectability of polarised broad H-alpha in Seyfert 2 galaxies is correlated to the IRAS f60/f25 flux ratio where only those Seyfert 2s with "warm" IRAS colours show polarised broad…

Astrophysics · Physics 2007-05-23 D. M. Alexander

Type 2 quasars are luminous Active Galactic Nuclei whose central engines are seen through large amounts of gas and dust. We present Spitzer spectra of twelve type 2 quasars selected on the basis of their optical emission line properties.…

Astrophysics · Physics 2010-05-27 Nadia L. Zakamska , Laura Gomez , Michael A. Strauss , Julian H. Krolik

We present the Spitzer 10-37um IRS high resolution (R~600) spectroscopic survey of the Seyfert galaxies of the 12 micron Galaxy Sample. The new spectra of 61 galaxies, with those already published, gives us a total of 91 12micron Seyfert…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Silvia Tommasin , Luigi Spinoglio , Matthew A. Malkan , Giovanni Fazio

We have studied the correlation among X-ray absorption, optical reddening and nuclear dust morphology in Seyfert 2 galaxies. Two main conclusions emerge: a) the Balmer decrement and the amount of X-ray absorption are anticorrelated on a…

Astrophysics · Physics 2009-11-06 M. Guainazzi , F. Fiore , G. Matt , G. C. Perola

We present results concerning the occurrence of Seyfert galaxies in a new automatically selected sample of nearby Compact Groups of galaxies (UZC-CGs). Seventeen Seyferts are found, constituting ~3% of the UZC-CG galaxy population. CGs…

Astrophysics · Physics 2009-11-10 B. Kelm , P. Focardi , V. Zitelli

[Abridged]We report on the broadband X-ray properties of a complete sample of absorbed Seyfert galaxies hard X-ray selected with INTEGRAL. The sample is composed of 33 sources: 15 are newly discovered above 20 keV while 18 are already known…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 A. De Rosa , F. Panessa , L. Bassani , A. Bazzano , A. Bird , R. Landi , A. Malizia , M. Molina , P. Ubertini

We present a new method for the statistical investigation into the distributions of the angle beta between the radio axis and the normal to the galactic disk for a sample of Seyfert galaxies. We discuss how further observations of the…

Astrophysics · Physics 2009-10-30 C. J. Clarke , A. L. Kinney , J. E. Pringle

We present a new accurate sample of narrow-line Seyfert 1 galaxies (NLS1s) in the southern hemisphere from the Six-degree Field Galaxy Survey (6dFGS). Based on the optical spectral features, 167 sources were classified as NLS1s. We derived…

Astrophysics of Galaxies · Physics 2018-09-19 S. Chen , M. Berton , G. La Mura , E. Congiu , V. Cracco , L. Foschini , J. H. Fan , S. Ciroi , P. Rafanelli , D. Bastieri

The first high resolution Spitzer IRS 9-37um spectra of 29 Seyfert galaxies (about one quarter) of the 12um Active Galaxy Sample are presented and discussed. The high resolution spectroscopy was obtained with corresponding off-source…

We review observations and theoretical models of X-ray/gamma-ray spectra of radio-quiet Seyfert galaxies and of Galactic black-hole candidates (in the hard spectral state). The observed spectra share all their basic components: an…

In this paper we report on the broadband X-ray properties of a complete sample of 33 absorbed Seyfert galaxies hard X-ray selected with integral. The high quality broadband spectra obtained with both xmm, and integral-IBIS data are well…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-21 A. De Rosa , F. Panessa , L. Bassani , A. Bazzano , A. J. Bird , R. Landi , A. Malizia , M. Molina , P. Ubertini

We analyze spectral properties of 1671 galaxies from the Stromlo-APM survey, selected to have 15 < b_J < 17.15 and having a mean redshift z = 0.05. This is a representative local sample of field galaxies, so the global properties of the…

Astrophysics · Physics 2009-10-31 L. Tresse , S. Maddox , J. Loveday , C. Singleton

We have observed a sample of 157 Seyfert galaxies with a 275 km baseline radio interferometer to search for compact, high brightness temperature radio emission from the active nucleus. We obtain the surprising result that compact radio…

Astrophysics · Physics 2009-10-22 A. L. Roy , R. P. Norris , M. J. Kesteven , E. R. Troup , J. E. Reynolds