scholarly journals Large-Scale Outflows in Edge-on Seyfert Galaxies. I. Optical Emission-Line Imaging and Optical Spectroscopy

1996 ◽  
Vol 105 ◽  
pp. 75 ◽  
Author(s):  
Edward J. M. Colbert ◽  
Stefi A. Baum ◽  
Jack F. Gallimore ◽  
Christopher P. O'Dea ◽  
Matthew D. Lehnert ◽  
...  
Keyword(s):  
Emission Line ◽  
Optical Spectroscopy ◽  
Large Scale ◽  
Optical Emission ◽  
Seyfert Galaxies ◽  
Line Imaging

An Emission-Line Imaging Survey of Early-Type Seyfert Galaxies. II. Implications for Unified Schemes

1996 ◽  
Vol 467 ◽  
pp. 197 ◽  
Author(s):  
John S. Mulchaey ◽  
Andrew S. Wilson ◽  
Zlatan Tsvetanov
Keyword(s):  
Emission Line ◽  
Seyfert Galaxies ◽  
Early Type ◽  
Line Imaging

scholarly journals An [O iii] search for extended emission around AGN with H i mapping: a distant cloud ionized by Mkn 1

2020 ◽  
Vol 496 (2) ◽  
pp. 1035-1050 ◽  
Author(s):  
Erin Darnell Knese ◽  
William C Keel ◽  
Greg Knese ◽  
Vardha N Bennert ◽  
Alexei Moiseev ◽  
...  
Keyword(s):  
Emission Line ◽  
Optical Spectroscopy ◽  
Large Fraction ◽  
Seyfert Galaxies ◽  
Emission Feature ◽  
Opening Angle ◽  
Entire Sample ◽  
Spatially Extended ◽  
Extended Emission

ABSTRACT Motivated by the discovery of large ionized clouds around AGN, and particularly the large fraction of those that are consistent with photoionized gaseous tidal debris, we searched for [O iii] emission around Seyfert galaxies previously mapped in H i, many with extended gas features. Of 26 Seyfert galaxies, we find one spatially extended emission feature, a discrete cloud projected ≈12 kpc SW from the centre of Mkn 1 and spanning a transverse extent of 8 kpc. Optical spectroscopy (Kast/Lick and SCORPIO/BTA) of this cloud confirms its association with the Mkn 1–NGC 451 galaxy pair, closely matching the kinematics of nearby H i structures, and reveals emission-line ratios requiring photoionization by the AGN at roughly the direct observed luminosity of the nucleus. For the entire sample, the full opening angle of the ionization cones (bicones) must be <20° if the AGNs are continuously bright for scales longer than the light-traveltimes to the H i structures. Since typical AGN ionization cones are observed to be much broader than this, our low detection fraction may add to evidence for the ubiquity of strong variations in AGN luminosity on scales 104–105 yr.

scholarly journals On the X-ray, optical emission line and black hole mass properties of local Seyfert galaxies

2006 ◽  
Vol 455 (1) ◽  
pp. 173-185 ◽  
Author(s):  
F. Panessa ◽  
L. Bassani ◽  
M. Cappi ◽  
M. Dadina ◽  
X. Barcons ◽  
...  
Keyword(s):  
Black Hole ◽  
Emission Line ◽  
Optical Emission ◽  
Seyfert Galaxies ◽  
Black Hole Mass ◽  
X Ray ◽  
Mass Properties

Radio-loud narrow-line Seyfert 1 galaxies with high-velocity outflows

2014 ◽  
Vol 10 (S312) ◽  
pp. 63-65 ◽  
Author(s):  
S. Komossa ◽  
D. Xu ◽  
J. A. Zensus
Keyword(s):  
Emission Line ◽  
Ionization Potential ◽  
High Velocity ◽  
Large Scale ◽  
Optical Emission ◽  
Strong Line ◽  
Narrow Line ◽  
Line Broadening ◽  
Central Engine ◽  
Radial Outflow

AbstractWe have studied four radio-loud Narrow-line Seyfert 1 (NLS1) galaxies with extreme optical emission-line shifts, indicating radial outflow velocities of up 2450 km s−1. The shifts are accompanied by strong line broadening, up to 2270 km s−1 in [NeV]. A significant ionization stratification (higher line shift at higher ionization potential) of most ions implies that we see a large-scale wind rather than single, localized jet-cloud interactions. The observations are consistent with a scenario, where the signatures of outflows are maximized because of a pole-on view into the central engine of these radio-loud NLS1 galaxies.

scholarly journals The Milliarcsecond Structure of Four Seyfert Galaxies at λ 18 cm

1994 ◽  
Vol 159 ◽  
pp. 426-426
Author(s):  
T. Ghosh ◽  
R.T. Schilizzi ◽  
G.K. Miley ◽  
A.G. Debruyn ◽  
M.J. Kukula ◽  
...  
Keyword(s):  
Black Hole ◽  
Emission Line ◽  
Optical Emission ◽  
Seyfert Galaxies ◽  
Massive Black Hole ◽  
Hole Model

The major contending scenarios capable of explaining various aspects of the Seyfert phenomenon in AGNs are (i) the Super-massive Black-Hole model and (ii) the Starburst model. Detailed optical emission-line and radio images of Seyfert nuclei, and their mutual correlations, provide important clues in evaluating the claims of each. Using the EVN at λ 18 cm, we have mapped four Seyfert galaxies, Mkn 1, 3, 231 and 463 at a resolution of ∼ 25 mas. The maps, and comparisons with images at other wavelengths, will be presented elsewhere (Ghosh et al. 1993, in preparation). Here, we present parameters derived from elliptical-Gaussian fits to all discernible components (Table 1).

scholarly journals The Origin of Weak Emission-Line AGNs

2012 ◽  
Vol 8 (S290) ◽  
pp. 267-268
Author(s):  
Yuan Liu ◽  
Jin Zhang ◽  
Shuang-Nan Zhang
Keyword(s):  
Emission Line ◽  
Optical Spectroscopy ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Early Stage ◽  
Optical Emission ◽  
Emission Lines ◽  
Near Infrared Spectra

AbstractSome abnormal AGNs are discovered in the SDSS data recently. The usual UV/optical emission lines are exceptionally weak in their UV/optical spectroscopy, though the shapes and luminosities of their continua are comparable with that of the normal AGNs. We investigated the optical variations and the near-infrared spectra of these weak emission-line AGNs. We propose that these AGNs can be interpreted as the early stage of an active cycle of AGNs.

An Emission-Line Imaging Survey of Early-Type Seyfert Galaxies. I. The Observations

1996 ◽  
Vol 102 ◽  
pp. 309 ◽  
Author(s):  
John S. Mulchaey ◽  
Andrew S. Wilson ◽  
Zlatan Tsvetanov
Keyword(s):  
Emission Line ◽  
Seyfert Galaxies ◽  
Early Type ◽  
Line Imaging
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