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相关论文: Hidden Broad Line Seyfert 2 Galaxies in the CfA an…

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The unified model of Seyfert galaxies suggests that there are hidden broad-line regions (HBLRs) in Seyfert 2 galaxies (S2s). However, there is increasing evidence for the appearance of a subclass of S2s lacking of HBLR (non-HBLR S2s). An…

天体物理学 · 物理学 2008-11-26 E. -P Zhang , J. -M. Wang

We extend the analysis presented in Tran (2001) of a spectropolarimetric survey of the CfA and 12micron samples of Seyfert 2 galaxies (S2s). We confirm that S2s with hidden broad line regions (HBLRs) tend to have hotter circumnuclear dust…

天体物理学 · 物理学 2009-11-07 Hien D. Tran

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…

天体物理学 · 物理学 2007-05-23 Hien D. Tran

We compile a large sample of 120 Seyfert 2 galaxies (Sy2s) which contains 49 hidden broad-line region (HBLR) Sy2s and 71 non-HBLR Sy2s. From the difference in the power sources between two groups, we test if HBLR Sy2s are dominated by…

高能天体物理现象 · 物理学 2015-05-27 Yu-Zhong Wu , En-Peng Zhang , Yan-Chun Liang , Cheng-Min Zhang , Yong-Heng Zhao

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…

天体物理学 · 物理学 2009-10-31 E. C. Moran , A. J. Barth , L. E. Kay , A. V. Filippenko

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…

天体物理学 · 物理学 2007-05-23 Edward C. Moran

We present a study of the local environment (<200 kpc/h) of 31 Hidden Broad Line Region (HBLR) and 43 non-HBLR Seyfert 2 galaxies (Sy2) in the nearby universe (z<0.04). To compare our findings, we constructed two control samples that match…

星系天体物理 · 物理学 2014-11-11 E. Koulouridis

The hidden broad-line regions (BLRs) in Seyfert 2 galaxies, which display broad emission lines (BELs) in their polarized spectra, are a key piece of evidence in support of the unified model for active galactic nuclei (AGNs). However, the…

星系天体物理 · 物理学 2017-05-03 Pu Du , Jian-Min Wang , Zhi-Xiang Zhang

We have detected a broad H alpha emission line in the polarized flux spectrum of the Seyfert 2 galaxy NGC 788, indicating that it contains an obscured Seyfert 1 nucleus. While such features have been observed in ~15 other Seyfert 2s, this…

天体物理学 · 物理学 2015-06-24 Laura E. Kay , Edward C. Moran

The origin of the unification model for Active Galactic Nuclei (AGN) was the detection of broad hydrogen recombination lines in the optical polarized spectrum of the Seyfert 2 galaxy (Sy2) NGC 1068. Since then, a search for the hidden…

According to the unified model of active galactic nuclei, Seyfert 2 galaxies are physically the same as Seyfert 1 objects and they possess a broad-line region (BLR), but it is hidden from the observer due to their orientation. In the past…

星系天体物理 · 物理学 2016-11-17 Georgi P. Petrov

The new $XMM-Newton$ data of seven Seyfert 2 galaxies with optical spectropolarimetric observations are presented. The analysis of 0.5 -- 10 keV spectra shows that all four Seyfert 2 galaxies with polarized broad lines (PBLs) are absorbed…

天体物理学 · 物理学 2009-11-13 X. W. Shu , J. X. Wang , P. Jiang

We present a compilation of radio, infrared, optical and hard X-ray (2-10kev) data for a sample of 90 Seyfert 2 galaxies(Sy2s) with spectropolarimetric observations (41 Sy2s with detection of polarized broad lines (PBL) and 49 without PBL).…

天体物理学 · 物理学 2016-08-17 Qiusheng Gu Jiehao Huang

We present the detection of extremely broad, double-peaked, highly polarized Halpha emission lines in the nuclei of the well-known Seyfert 2 galaxies NGC 2110 and NGC 5252. These hidden broad Halpha emission lines, visible only in scattered…

宇宙学与河外天体物理 · 物理学 2010-02-23 Hien D. Tran

We investigate the ionization mechanisms for hidden broad-line region (HBLR) and non-HBLR Seyfert 2 galaxies by comparing some optical emission line ratios. We note that the [N II]6583/H_alpha ratio of the non-HBLR Seyfert 2 galaxies is…

宇宙学与河外天体物理 · 物理学 2015-05-28 Po-Chieh Yu , Chorng-Yuan Hwang

We report the discovery of the scattered emission from a hidden broad-line region (BLR) in a Seyfert 2 galaxy, Mrk 573, based on our recent spectropolarimetric observation performed at the Subaru Telescope. This object has been regarded as…

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…

天体物理学 · 物理学 2008-11-26 Himel Ghosh , Richard W. Pogge , Smita Mathur , Paul Martini , Joseph C. Shields

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…

天体物理学 · 物理学 2009-11-06 S. L. Lumsden , C. A. Heisler , J. A. Bailey , J. H. Hough , S. Young

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…

天体物理学 · 物理学 2008-11-26 W. Bian , Q. Gu

We analyzed a large sample of SDSS spectra of Seyfert galaxies, subdividing Seyfert 1s based on their narrow-to-broad Halpha components. Comparing their narrow-lines (NL) to Seyfert2s in line-ratio diagrams, most of the NL of strong Sy 1.0…

星系天体物理 · 物理学 2026-01-13 Matthew Malkan , Lisbeth Jensen , Lei Hao
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