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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…

Ground based long slit spectroscopic observations of the nuclear region of NGC 5252, and Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) spectra of the nucleus and two bright knots located 0.36" NE and 0.31" SW from it, show…

Astrophysics · Physics 2007-05-23 A. C. Goncalves , P. Veron , M. -P. Veron-Cetty

We present a multi-wavelength study of the radio-loud narrow line Seyfert 1 galaxy (NLSy1), 1H 0323+342, detected by Fermi Gamma Ray Space Telescope. Multi-band light curves show many orphan X-ray and optical flares having no corresponding…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Vaidehi S. Paliya , S. Sahayanathan , M. L. Parker , A. C. Fabian , C. S. Stalin , Ayesha Anjum , S. B. Pandey

Emission-line studies in the active galactic nuclei (AGNs), particularly those utilizing high spatial resolution, provide the most accurate method to determine critical quantities of the central engine and of the gas a few tens of parsecs…

Most of the optically classified low ionisation narrow emission-line regions (LINERs) nuclei host an active galactic nuclei (AGN). However, how they fit into the unified model (UM) of AGN is still an open question. The aims of this work are…

Up to 40% of galaxies in the local universe host a low-luminosity active galactic nucleus (LLAGN), making it vital to understand this mode of black hole accretion. However, the presence or absence of Seyfert-like geometries - an accretion…

The presence of an obscuring torus around the nucleus of Seyfert galaxies, as supposed in the popular unification scheme, can strongly modify the X--ray spectrum for both type 1 and 2 Seyfert galaxies. We find that if the torus is Compton…

Astrophysics · Physics 2015-06-24 Gabriele Ghisellini , Francesco Haardt , Giorgio Matt

We present 8-13 micron imaging and spectroscopy of 9 type 1 and 10 type 2 AGN obtained with the VLT/VISIR instrument at spatial resolution <100 pc. The emission from the host galaxy sources is resolved out in most cases. The silicate…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 S. F. Hoenig , M. Kishimoto , P. Gandhi , A. Smette , D. Asmus , W. Duschl , M. Polletta , G. Weigelt

We have decomposed the broad H-alpha, H-beta and H-gamma lines of 90 Active Galactic Nuclei (AGNs) into a superposition of a very broad and an intermediate Gaussian components (VBGC and IMGC) and discovered that the two Gaussian components…

Astrophysics of Galaxies · Physics 2009-01-21 Ling Zhu , ShuangNan Zhang , Sumin Tang

We present the results of a ~160 ks-long XMM-Newton observation of the Seyfert 1 galaxy Mrk 279. The spectrum shows evidence of both broad and narrow emission features. The Fe K alpha line may be equally well explained by a single broad…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 E. Costantini , J. S. Kaastra , K. Korista , J. Ebrero , N. Arav , G. Kriss , K. C. Steenbrugge

A two-components model for Broad Line Region (BLR) of Active Galactic Nuclei (AGN) has been suggested for many years but not widely accepted (e.g., Hu et al. 2008; Sulentic et al. 2000; Brotherton et al. 1996; Mason et al. 1996). This model…

Astrophysics · Physics 2012-09-14 Ling Zhu , Shuang Nan Zhang , Sumin Tang

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 present optical spectropolarimetry of the nuclei of 36 Seyfert 1 galaxies, obtained with the William Herschel and the Anglo-Australian Telescopes from 1996 to 1999. In 20 of these, the optical emission from the active nucleus is…

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

Coronal lines (CLs), which arise from collisionally excited forbidden transitions from highly ionized species, are a powerful diagnostic tool in uncovering active galactic nuclei (AGNs) and constraining their properties. However, recent…

Astrophysics of Galaxies · Physics 2025-02-24 William Matzko , Shobita Satyapal , Michael Reefe , Jeffrey McKaig , Remington O. Sexton , Sara Doan

Here we describe the \emph{Siding Spring Southern Seyfert Spectroscopic Snapshot Survey} (S7) and present results on 64 galaxies drawn from the first data release. The S7 uses the Wide Field Spectrograph (WiFeS) mounted on the ANU 2.3m…

We describe the results of a detailed study of the polarization properties of the broad H-alpha emission line in Type 1 Seyfert nuclei. Our analysis of these data points to a model in which the broad Balmer lines are emitted by a rotating…

Astrophysics · Physics 2007-05-23 Andy Robinson , David J. Axon , James E. Smith

We present a detailed investigation of the near-to-far infrared (IR) spectral energy distribution (SED) of a large sample of Spitzer-observed active galactic nuclei (AGN). We fitted the spectra of 51 narrow line Seyfert 1 galaxies (NLS1s)…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Rivay Mor , Hagai Netzer

In order to examine how narrow emission-line flux ratios depend on the Seyfert type, we compiled various narrow emission-line flux ratios of 355 Seyfert galaxies from the literature. We present in this paper that the intensity of the…

Astrophysics · Physics 2015-06-24 Tohru Nagao , Takashi Murayama , Yoshiaki Taniguchi

We present a spatially resolved Baldwin-Phillips-Terlevich analysis of the narrow-line region (NLR) in the low-ionization nuclear emission-line region (LINER) I galaxy NGC 5005 using Hubble Space Telescope narrowband imaging of [O…

Astrophysics of Galaxies · Physics 2025-06-19 Anna Trindade Falcão , G. Fabbiano , M. Elvis , P. Zhu , S. Kraemer , W. P. Maksym , R. Middei , D. L. Król

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
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