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Related papers: Are Seyfert 2 Galaxies without Polarized Broad Emi…

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We analyze the 0.5-10 keV spectra of six Seyfert 2 galaxies observed with the X-ray satellite ASCA: Mrk 3, Mrk 348, Mrk 1210, Mrk 477, NGC 7212, and Was 49b. These galaxies were selected based on their possession of optical polarized broad…

Astrophysics · Physics 2016-08-30 Hisamitsu Awaki , Shiro Ueno , Yoshiaki Taniguchi , Kimberly A. Weaver

We study the X-ray spectra of a sample of 19 obscured, optically-selected Seyfert galaxies (Sy 1.8, 1.9 and 2) in the local universe ($d \leq 175$~Mpc), drawn from the CfA Seyfert sample. Our analysis is driven by the high sensitivity of…

High Energy Astrophysical Phenomena · Physics 2020-10-14 E. S. Kammoun , J. M. Miller , M. Koss , K. Oh , A. Zoghbi , R. F. Mushotzky , D. Barret , E. Behar , W. N. Brandt , L. W. Brenneman , J. S. Kaastra , A. M. Lohfink , D. Proga , D. Stern

The Unification Model for active galactic nuclei posits that Seyfert 2s are intrinsically like Seyfert 1s, but that their broad-line regions (BLRs) are hidden from our view. A Seyfert 2 nucleus that truly lacked a BLR, instead of simply…

Astrophysics · Physics 2008-11-26 Himel Ghosh , Richard W. Pogge , Smita Mathur , Paul Martini , Joseph C. Shields

We have used X-ray spectra to measure attenuating columns in a large sample of Seyfert galaxies. Over 30 of these sources have resolved radio jets, allowing the relative orientation of the nucleus and host galaxy to be constrained. We have…

Astrophysics · Physics 2017-08-23 Jonathan Gelbord , K. A. Weaver , T. Yaqoob

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 have identified 12 Seyfert 1 galaxies that exhibit optical polarization spectra similar to those of Seyfert 2 galaxies in which polarized broad-lines are detected. We present new spectropolarimetric observations of 3 of them: Was 45, Mrk…

Astrophysics · Physics 2008-11-26 J. E. Smith , A. Robinson , D. M. Alexander , S. Young , D. J. Axon , Elizabeth A. Corbett

We present the combined Chandra and Swift-BAT spectral analysis of seven Seyfert 2 galaxies selected from the Swift-BAT 100-month catalog. We selected nearby (z<=0.03) sources lacking of a ROSAT counterpart and never previously observed…

High Energy Astrophysical Phenomena · Physics 2017-02-22 Stefano Marchesi , Marco Ajello , Andrea Comastri , Giancarlo Cusumano , Valentina La Parola , Alberto Segreto

Using a large sample of 90 Seyfert 2 galaxies (Sy2s) with spectropolarimetric observations, we tested the suggestion that the presence of hidden broad-line regions (HBLRs) in Sy2s is dependent upon the Eddington ratio. The stellar velocity…

Astrophysics · Physics 2008-11-26 W. Bian , Q. Gu

We present a study of the variations in the absorbing column density of 25 X-ray defined Seyfert 2 galaxies, as inferred from hard X-ray observations, on timescales from months to several years. We show that a significant variation of N$_H$…

Astrophysics · Physics 2009-11-06 G. Risaliti , M. Elvis , F. Nicastro

We present evidence for a strong correlation between the gaseous absorbing column density towards type 2 Seyfert nuclei and the presence of a stellar bar in their host galaxies. Strongly barred Seyfert 2 galaxies have an average Nh that is…

Astrophysics · Physics 2007-05-23 R. Maiolino , G. Risaliti , M. Salvati

We systematically analyzed the high-quality Suzaku data of 88 Seyfert galaxies. We obtained a clear relation between the absorption column density and the equivalent width of the 6.4 keV line above 10$^{23}$ cm$^{-2}$, suggesting a…

We consider the sample of Tran (2001) to study the X-ray properties of Seyfert 2 galaxies with and without polarized broad lines.

Astrophysics · Physics 2007-05-23 Andrea Martocchia , Giorgio Matt

JHKL'M (1-5 micron) imaging of a sample of Seyfert (Sy) 2 galaxies is presented. We confirm that the 1-2.2 micron nuclear continuum of some Sy 2s is dominated by stellar emission, whereas the continuum emission at longer wavelengths (3-5…

Astrophysics · Physics 2009-10-31 A. Alonso-Herrero , A. C. Quillen , C. Simpson , A. Efstathiou , M. J. Ward

The results of spectropolarimetry surveys of obscured AGNs are reviewed, paying special attention to their implications for the existence of two populations of type 2 Seyfert galaxies -- hidden Seyfert 1s and "true" Seyfert 2s. In this…

Astrophysics · Physics 2007-05-23 Edward C. Moran

We present the results of a Suzaku monitoring campaign of the Seyfert 2 galaxy, NGC7582. The source is characterized by very rapid (on timescales even lower than a day) changes of the column density of an inner absorber, together with the…

Astrophysics of Galaxies · Physics 2011-02-11 Stefano Bianchi , Enrico Piconcelli , Marco Chiaberge , Elena Jimenez Bailon , Giorgio Matt , Fabrizio Fiore

A number of studies have shown that the visibility of scattered broad emission lines in Seyfert 2 galaxies is strongly dependent on the IRAS f_60/f_25 flux ratio, where those Seyfert 2s with `warm' IRAS colours show polarised broad line…

Astrophysics · Physics 2009-11-07 S. L. Lumsden , D. M. Alexander

We report the results of a spectropolarimetric survey of a complete far infrared selected sample of Seyfert 2 galaxies. We have found polarized broad Halpha emission in one new source, NGC5995. In the sample as a whole, there is a clear…

Astrophysics · Physics 2009-11-06 S. L. Lumsden , C. A. Heisler , J. A. Bailey , J. H. Hough , S. Young

Hawkins (2004) reported on a class of "naked" AGN characterized by strong amplitude optical brightness variability and the complete absence of broad emission lines in the optical spectrum. The variability suggests that the nucleus is seen…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 F. Panessa , F. J. Carrera , S. Bianchi , A. Corral , F. Gastaldello , X. Barcons , L. Bassani , G. Matt , L. Monaco

In this paper we discuss the X-ray properties of 49 local (z<0.035) Seyfert 2 galaxies with HST/WFC2 high-resolution optical coverage. It includes the results of 26 still unpublished Chandra and XMM-Newton observations, which yield 25 (22)…

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

Results obtained from an X-ray spectral survey of nearby Seyfert galaxies using XMM--Newton are reported. The sample was optically selected, well defined, complete in B mag, and distance limited: it consists of the nearest (D<22 Mpc) 27…