Line variability and the broad emission line region of quasi-stellar objects. III - Line profiles and velocity field

1988 ◽  
Vol 333 ◽  
pp. 188 ◽  
Author(s):  
Wei Zheng
Keyword(s):  
Velocity Field ◽  
Emission Line ◽  
Line Profiles ◽  
Stellar Objects ◽  
Broad Emission ◽  
Line Region ◽  
Quasi Stellar Objects ◽  
Broad Emission Line

scholarly journals Spectral variability of the 3C 390.3 nucleus for more than 20 years – II.  Variability of the broad emission-line profiles and He ii λ4686 Å emission-line fluxes

2020 ◽  
Vol 495 (1) ◽  
pp. 971-980
Author(s):  
S G Sergeev
Keyword(s):  
Emission Line ◽  
Emission Region ◽  
Line Profiles ◽  
Broad Emission ◽  
Line Region ◽  
Balmer Lines ◽  
Optical Continuum ◽  
Broad Emission Line ◽  
Disc Configuration ◽  
Factor C

ABSTRACT Results of the analysis of the variability of the H β and H α broad emission-line profiles and the He ii λ4686 Å emission-line fluxes in the 3C 390.3 nucleus during 1992–2014 are present. The observed velocity-dependent lag for the Balmer lines is similar to that expected from the Keplerian disc configuration, although there are some differences. Probably, a radial infall motion can be present in the broad-line region of 3C 390.3 in addition to the Keplerian rotation. The lag of the broad He ii line is 26 ± 8 d, significantly less than that of the Balmer lines, so the He ii emission region is much smaller in size. In terms of the power-law relationship between line and optical continuum fluxes with slowly varying scale factor c(t): $F_{\rm line}\propto c(t)\, F_{\rm cont}^a$, the power a is 1.03 for the broad He ii line, while according to Paper I, the power is equal to 0.77 and 0.54 for the broad H β and H α lines, respectively. It means that the variability amplitude is the largest in the He ii, less in H β, and more less in H α. However, the Balmer lines contain a long-term trend that is not seen in the helium line. The narrow He ii line is variable with the amplitude (max-to-min ratio) Rmax ≈ 3, which is much greater than the variability amplitudes of both the narrow Balmer lines and the narrow [O iii] λ5007 Å line.

scholarly journals Complex broad emission line profiles of AGN – Geometry of the broad line region

2009 ◽  
Vol 53 (7-10) ◽  
pp. 121-127 ◽  
Author(s):  
E. Bon ◽  
N. Gavrilović ◽  
G. La Mura ◽  
L.Č. Popović
Keyword(s):  
Emission Line ◽  
Broad Line ◽  
Line Profiles ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line

scholarly journals The Kinematics of Quasar Broad Emission Line Regions Using a Disk-Wind Model

2017 ◽  
Vol 34 ◽  
Author(s):  
Suk Yee Yong ◽  
Rachel L. Webster ◽  
Anthea L. King ◽  
Nicholas F. Bate ◽  
Matthew J. O’Dowd ◽  
...  
Keyword(s):  
Emission Line ◽  
Line Profile ◽  
Inclination Angle ◽  
Opening Angle ◽  
Line Profiles ◽  
Wind Model ◽  
Disk Wind ◽  
Reverberation Mapping ◽  
Broad Emission ◽  
Line Region

AbstractThe structure and kinematics of the broad line region in quasars are still unknown. One popular model is the disk-wind model that offers a geometric unification of a quasar based on the viewing angle. We construct a simple kinematical disk-wind model with a narrow outflowing wind angle. The model is combined with radiative transfer in the Sobolev, or high velocity, limit. We examine how angle of viewing affects the observed characteristics of the emission line. The line profiles were found to exhibit distinct properties depending on the orientation, wind opening angle, and region of the wind where the emission arises.At low inclination angle (close to face-on), we find that the shape of the emission line is asymmetric, narrow, and significantly blueshifted. As the inclination angle increases (close to edge-on), the line profile becomes more symmetric, broader, and less blueshifted. Additionally, lines that arise close to the base of the disk wind, near the accretion disk, tend to be broad and symmetric. Single-peaked line profiles are recovered for the intermediate and equatorial wind. The model is also able to reproduce a faster response in either the red or blue sides of the line profile, consistent with reverberation mapping studies.

scholarly journals Near infrared hydrogen emission line ratios as diagnostics of the broad emission line region

2012 ◽  
Vol 372 ◽  
pp. 012069
Author(s):  
Andrea J Ruff ◽  
David J E Floyd ◽  
Kirk T Korista ◽  
Rachel L Webster ◽  
Ryan L Porter ◽  
...  
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Hydrogen Emission ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line ◽  
Hydrogen Emission Line

scholarly journals Velocity Diagnostics of the Broad Emission-Line Region of Active Galactic Nuclei

1997 ◽  
Vol 159 ◽  
pp. 175-178 ◽  
Author(s):  
Brian Espey
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Nuclear Region ◽  
Driving Mechanisms ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line ◽  
Ongoing Project

AbstractWe present a brief review of emission-line velocity differences, and describe an ongoing project to determine the driving mechanisms responsible. We conclude with a brief outline of the use of velocity differences as probes of the conditions in the nuclear region of AGNs.

scholarly journals The Nature and Origin of Structure in Broad Emission Line Profiles

1997 ◽  
Vol 159 ◽  
pp. 193-194 ◽  
Author(s):  
C. Martin Gaskell ◽  
Stephanie A. Snedden
Keyword(s):  
Emission Line ◽  
The Other ◽  
Central Component ◽  
Balmer Line ◽  
Line Profiles ◽  
Broad Emission ◽  
Broad Emission Line

AbstractWe postulate that all structure in broad lines can be explained by a central component (at the systemic redshift) and the addition of two ‘displaced components’, one blueshifted and the other redshifted. We have been able to successfully classify all Balmer-line profiles on this basis. 3C 390.3-type objects are merely examples where the shifts of the displaced components are unusually large. We believe that the displaced peaks are less prominent in the UV lines because the higher ionization lines are broader.

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