English
Related papers

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

200 papers

We present Chandra ACIS-S observations of the enigmatic Seyfert-2 galaxy NGC4698. This object together with several other bona-fide Seyfert-2 galaxies show no absorption in the low spatial resolution ASCA data, in contrast to the standard…

Astrophysics · Physics 2016-08-30 I. Georgantopoulos , A. Zezas

The Unification Model of AGN suggests that all AGN galaxies should exhibit similar line ratios in their spectra. NGC 5548, a Seyfert I, underwent obscuration -- similar to naturally obscured Seyfert II galaxies -- due to an outflowing…

Astrophysics of Galaxies · Physics 2025-08-19 Divya Patel , Maryam Dehghanian , Gary Ferland

We present the results of a near-infrared and X-ray study of the Seyfert 2 galaxy NGC 3281. Emission from the Seyfert nucleus is detected in both regions of the electromagnetic spectrum, allowing us to infer both the equivalent line of…

Astrophysics · Physics 2009-10-30 Chris Simpson , Subaru Telescope

We present the results of an intermediate-resolution (1.5\AA) spectroscopic study of 17 X-ray luminous narrow emission-line galaxies previously identified in the Cambridge-Cambridge {\it ROSAT} Serendipity Survey and the {\it Einstein}…

Astrophysics · Physics 2015-06-24 B. J. Boyle , R. G. McMahon , B. J. Wiles , M. Elvis

We present near-infrared 1.5 - 2.5 micron moderate resolution long-slit spectra of two Seyfert 1 galaxies (NGC 1097 and NGC 1566), three Seyfert 2s (NGC 1386, NGC 4945 and NGC 5128) and one Seyfert 1.5 (NGC 3227), both parallel to…

Astrophysics · Physics 2009-11-07 J. Reunanen , J. K. Kotilainen , M. A. Prieto

Here we present the results of a Suzaku observation of the Broad Line Radio Galaxy 3C 445. We confirm the results obtained with the previous X-ray observations which unveiled the presence of several soft X-ray emission lines and an overall…

High Energy Astrophysical Phenomena · Physics 2015-05-27 V. Braito , J. N. Reeves , R. M. Sambruna , J. Gofford

We study the radio properties at 1.4 GHz of Seyfert galaxies with strong forbidden high-ionization lines (FHILs), selected from the Sloan Digital Sky Survey - a large-sized sample containing nearly equal proportion of diverse range of…

Astrophysics of Galaxies · Physics 2016-01-05 Dharam V. Lal

The excellent soft X-ray sensitivity of the PSPC detector onboard the ROSAT satellite provided the first chance to study precisely the spectral and timing properties of Narrow-Line Seyfert 1 galaxies. ROSAT observations of Narrow-Line…

Astrophysics · Physics 2009-10-31 Th. Boller

Half of the Seyfert-2 galaxies escaped detection of broad lines in their polarised spectra observed so far. Some authors have suspected that these non-HBLRs contain real Sy2 nuclei without intrinsic broad line region hidden behind a dust…

From detailed spectral analysis of a large sample of low-redshift active galactic nuclei (AGNs) selected from the Sloan Digital Sky Survey, we demonstrate---statistically for the first time---that narrow optical Fe II emission lines, both…

Astrophysics of Galaxies · Physics 2010-09-14 Xiao-Bo Dong , Luis C. Ho , Jian-Guo Wang , Ting-Gui Wang , Huiyuan Wang , Xiaohui Fan , Hongyan Zhou

We analyze X-ray spectra and images of a sample of Seyfert 2 galaxies that unambiguously contain starbursts, based on their optical and UV characteristics. Although all sample members contain active galactic nuclei (AGNs), supermassive…

Astrophysics · Physics 2009-10-31 N. A. Levenson , K. A. Weaver , T. M. Heckman

(Abridged) We analyzed the {\it Chandra} and {\it XMM-Newton} archival observations for 72 type 2 quasars at $z<1$. These objects were was selected based on the [O III]$\lambda$5007 optical emission line which we assume to be an approximate…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Jianjun Jia , Andrew Ptak , Timothy Heckman , Nadia Zakamska

We present sub-arcsec near-infrared 1.5 - 2.5 micron moderate resolution long-slit spectra of eight nearby Seyfert galaxies (z<0.01), both parallel to the ionization cone and perpendicular to it. These spectra complement similar data on six…

Astrophysics · Physics 2009-11-07 J. Reunanen , J. Kotilainen , M. A. Prieto

We present a study of X-ray column density variability in Seyfert 2 galaxies. We show that variations in N_H are observed in almost all the objects with multiple hard X-ray observations. Variation timescales (as short as a few months in…

Astrophysics · Physics 2009-11-07 G. Risaliti , M. Elvis , F. Nicastro

The Seyfert 2 galaxy NGC 7674 has been observed within the BeppoSAX Core Programme with the onboard narrow field instruments between 0.1 and 100 keV. The broad-band spectrum shows four most relevant spectral components: a) a soft excess…

We present the results of ROSAT All-Sky Survey observations of Seyfert and IR-luminous galaxies from the Extended 12 Micron Galaxy Sample and the optically-selected CfA Sample. Roughly half of the Seyferts (mostly Seyfert 1s) have been…

Astrophysics · Physics 2009-10-28 Brian Rush , Matthew A. Malkan , Henner H. Fink , Wolfgang Voges

We report on the unveiling of the nature of the unidentified X-ray source 3XMM J005450.3-373849 as a Seyfert-2 galaxy located behind the spiral galaxy NGC 300 using Hubble Space Telescope data, new spectroscopic Gemini observations and…

Astrophysics of Galaxies · Physics 2016-05-25 J. A. Combi , F. Garcia , M. J. Rodriguez , R. Gamen , S. A. Cellone

We present the results of an optical spectroscopic survey designed to search for low-luminosity, "dwarf" Seyfert nuclei in a magnitude-limited sample of 486 bright, northern galaxies. Moderate-resolution spectra of exceptionally high…

Astrophysics · Physics 2010-12-09 Luis C. Ho , Alexei V. Filippenko , Wallace L. W. Sargent , Chien Y. Peng

We present the results of X-ray spectral analysis of the Seyfert type 2 galaxy Mrk 417 observed by the NuSTAR (3-60 keV) and the Swift/BAT (14-150) observatories. The NuSTAR data shows a good fit with a baseline model which composed of an…

High Energy Astrophysical Phenomena · Physics 2020-05-26 O. V. Kompaniiets , A. A. Vasylenko

In this concluding part of the series of three papers dedicated to the Swift/BAT hard X-ray survey (BXS), we focus on the X-ray spectral analysis and statistical properties of the source sample. Using a dedicated method to extract…