The kinematics of the narrow-line region in active galaxies and quasars. III - Correlations with the broad-line region and radio emission

1984 ◽  
Vol 281 ◽  
pp. 525 ◽  
Author(s):  
T. M. Heckman ◽  
G. K. Miley ◽  
R. F. Green
Keyword(s):  
Radio Emission ◽  
Active Galaxies ◽  
Broad Line ◽  
Narrow Line ◽  
Broad Line Region ◽  
Line Region ◽  
Narrow Line Region

scholarly journals Near-IR Spectroscopy of High-z QSOs: Relating the Broad and Narrow-Line Regions

1997 ◽  
Vol 159 ◽  
pp. 258-259
Author(s):  
M.S. Brotherton
Keyword(s):  
Simple Model ◽  
Broad Line ◽  
Narrow Line ◽  
Strong Correlations ◽  
Broad Line Region ◽  
Near Ir ◽  
Line Region ◽  
Derived Properties ◽  
Narrow Line Region ◽  
Line Widths

Recent investigations of the broad UV lines in luminous QSOs identified strong correlations involving emission-line widths, shifts, equivalent widths, and ratios (Francis et al. 1992; Wills et al. 1993; Brotherton et al. 1994a, b). A simple model developed to explain these trends approximates UV broad lines as emission from two regions, an intermediate-line region (ILR), and a very broad-line region (VBLR), together comprising the traditional broad-line region (BLR). The observed and derived properties for the ILR and VBLR are summarized in Table 1, along with typical values for the narrow-line region (NLR).

scholarly journals Unification of Radio Galaxies

1998 ◽  
Vol 164 ◽  
pp. 81-82
Author(s):  
M.H. Cohen ◽  
P.M. Ogle ◽  
H.D. Iran ◽  
R.W. Goodrich
Keyword(s):  
Radio Galaxies ◽  
Broad Line ◽  
Narrow Line ◽  
Spectral Classification ◽  
Broad Line Region ◽  
Line Region ◽  
Direct View

AbstractMany FR 2 narrow-line radio galaxies also display polarized broad lines. The broad-line region is hidden from direct view and is seen by reflection (ie scattering). In these objects the spectral classification is controlled by the aspect at which they are viewed.

scholarly journals Dusty origin of the Broad Line Region in active galaxies

2012 ◽  
Vol 8 (S290) ◽  
pp. 21-24
Author(s):  
Bozena Czerny ◽  
Krzysztof Hryniewicz ◽  
Janusz Kaluzny ◽  
Ishita Maity
Keyword(s):  
Black Hole ◽  
Active Galaxies ◽  
Emission Lines ◽  
Broad Line ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region ◽  
Interesting Possibility ◽  
Considerable Complexity

AbstractThe most characteristic property of active galaxies, including quasars, are prominent broad emission lines. I will discuss an interesting possibility that dust is responsible for this phenomenon. The dust is known to be present in quasars in the form of a dusty/molecular torus which results in complexity of the appearance of active galaxies. However, this dust is located further from the black hole than the Broad Line Region. We propose that the dust is present also closer in and it is actually responsible for formation of the broad emission lines. The argument is based on determination of the temperature of the disk atmosphere underlying the Broad Line Region: it is close to 1000 K, independently from the black hole mass and accretion rate of the object. The mechanism is simple and universal but leads to a considerable complexity of the active nucleus surrounding. The understanding the formation of BLR opens a way to use it reliably - in combination with reverberation measurement of its size - as standard candles in cosmology.

scholarly journals Gravitation and Jet Induced Velocities in the Narrow Line Region of Active Galaxies

1989 ◽  
Vol 8 ◽  
pp. 423-427 ◽  
Author(s):  
Mark Whittle
Keyword(s):  
Active Galaxies ◽  
Basic Question ◽  
Radio Sources ◽  
Narrow Line ◽  
Radio Luminosity ◽  
Natural Explanation ◽  
Radio Jets ◽  
Line Region ◽  
Ngc 1068 ◽  
Narrow Line Region

The basic question I want to address is : “What mechanism or mechanisms accelerate the gas in the narrow line region of active galaxies, yielding the observed profile shapes.” At the present time there is no generally accepted answer to this question. Part of the problem dates back to the first few Seyferts that were discovered which, in retrospect, seem to have had anomalously broad lines. For example NGC 1068, MKN 3, and MKN 78 have [OIII] λ 5007 FWHM ~ 1000 km s-1, which is clearly greater than anything associated with a normal galaxy velocity fields. An obvious implication was that these high velocities were in some way related to the activity. This view was reinforced by the discovery of a correlation between [OIII] FWHM and non-thermal radio luminosity (Wilson and Willis 1981). When many radio sources were found to have linear double or triple morphology (e.g. Ulvestad and Wilson 1984a,b), a natural explanation seemed to be outflowing radio jets which stir up the narrow line region and thus generate the correlation between line width and radio luminosity.

scholarly journals MERLIN Observations of Seyfert Nuclei

1994 ◽  
Vol 159 ◽  
pp. 430-430
Author(s):  
A. Pedlar ◽  
M.J. Kukula
Keyword(s):  
Radio Emission ◽  
Adaptive Optics ◽  
Narrow Line ◽  
High Quality ◽  
Optical Images ◽  
Line Region ◽  
Narrow Line Region

Radio emission from Seyfert nuclei appears to be intimately related to narrow line region (NLR) of ionised gas. Both regions have an extent of a few hundred parsecs corresponding to typically a few arcsec, and are only marginally resolved by ground based observations. HST and adaptive optics are giving optical images of the ionised gas with angular resolutions of order 0.1″. It is essential that high quality radio images are available with similar resolution so that models relating the two regions can be tested. The extended MERLIN is ideally suited for this task. It has angular resolutions of 0.05″ at 5GHz and 0.13″ at 1.5GHz and sensitivities of a few 10s of μJy. In this contribution we shall summarise the results on two objects.

scholarly journals Radiation Hydrodynamics of the Broad Line Region in Seyfert Galaxies and Quasars

1986 ◽  
Vol 89 ◽  
pp. 346-368
Author(s):  
William G. Mathews
Keyword(s):  
Seyfert Galaxies ◽  
Active Galaxies ◽  
Radiation Hydrodynamics ◽  
Acceleration Process ◽  
Broad Line ◽  
Partial Explanation ◽  
Theoretical Understanding ◽  
Broad Line Region ◽  
Line Region ◽  
Intense Radiation

The broad line region in quasars and in the nuclei of active galaxies is the site of remarkable hydrodynamic activity unprecedented elsewhere in the universe. Considerable theoretical effort has been directed to determine how this intense radiation is related to high velocity gas motions in these small regions, which, because of their great distances, cannot be resolved by direct observation. A better theoretical understanding of the nature of the broad line-emitting gas involves many novel aspects of radiation hydrodynamics and may eventually provide insights into the nature of the mysterious quasar phenomenon itself.Continuum and emission line properties of active galaxies and quasars are sufficiently similar that there is little doubt that both can be accounted for by a similar or closely related physical model. The main difference is one of luminosity; typical quasars are considerably brighter than Seyfert galaxies.In the discussion below the relevant observations of quasars and active galaxies are briefly reviewed with an emphasis on the physical properties of the line-emitting gas and its immediate environment. Arguments that support the importance of radiation forces in producing the observed gas velocities are summarized. Finally, the nature of the acceleration process is described with particular attention paid to the various instabilities that may be present and which are generally characteristic of situations in which plasma velocities result directly from the deposition of radiative momentum. In fact, these troublesome instabilities suggest that radiative forces, although very strong, may provide only a partial explanation of the gasdynamical activity observed.

scholarly journals The relation between the properties of the NLR in narrow-line Seyfert 1 galaxies and the accretion rate

2006 ◽  
Vol 2 (S238) ◽  
pp. 473-474
Author(s):  
Dawei Xu ◽  
Stefanie Komossa
Keyword(s):  
Accretion Rate ◽  
Sloan Digital Sky Survey ◽  
Physical Parameters ◽  
Broad Line ◽  
Narrow Line ◽  
Black Hole Mass ◽  
Line Region ◽  
Sky Survey ◽  
Narrow Line Region ◽  
The Relationship

AbstractWe present a systematic study of the properties of the narrow-line region (NLR) of narrow-line Seyfert 1 galaxies (NLS1s) using Sloan Digital Sky Survey (SDSS) spectroscopy. Various correlations between the observed parameters and physical properties of NLS1s and broad-line Seyfert 1 galaxies (BLS1s) are detected. We search for possible origins of these trends by employing correlation analyses. We further investigate the relationship between black hole mass, Eddington ratio (L/LEdd) and physical parameters of the NLR.

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