scholarly journals The Hβ line shape of Akn 120

2000 ◽  
pp. 7-33 ◽  
Author(s):  
N. Stanic ◽  
L.C. Popovic ◽  
A. Kubicela ◽  
E. Bon
Keyword(s):  
Line Shape ◽  
Crimean Astrophysical Observatory ◽  
Broad Line ◽  
Line Profiles ◽  
Shape Variation

We present here the Akn 120 H? line profiles from 97 spectra observed from 1977 till 1990 at Crimean Astrophysical Observatory (Appendix 1). The H? line has been fitted with three broad and one narrow Gaussian throughout the whole considered period. The central broad components of the H? and a shelf cause the H? line shape variation. Three broad Gaussians may suggest the existence of three broad line regions in the central part of the Akn 120. Long-term H? line shape variations in spectra of this galaxy are discussed.

SDSS J154751.94+025550 with double-peaked broad H β but single-peaked broad H α: a candidate for central binary black hole system?

2021 ◽  
Vol 507 (4) ◽  
pp. 5205-5213
Author(s):  
XueGuang Zhang
Keyword(s):  
Black Hole ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
Broad Line ◽  
Line Profiles ◽  
Physical Conditions ◽  
Binary Black Hole ◽  
Sinusoidal Function

ABSTRACT In this manuscript, an interesting blue active galactic nuclei (AGNs) SDSS J154751.94+025550 (=SDSS J1547) is reported with very different line profiles of broad Balmer emission lines: double-peaked broad H β but single-peaked broad H α. SDSS J1547 is the first AGN with detailed discussions on very different line profiles of the broad Balmer emission lines, besides the simply mentioned different broad lines in the candidate for a binary black hole (BBH) system in SDSS J0159+0105. The very different line profiles of the broad Balmer emission lines can be well explained by different physical conditions to two central BLRs in a central BBH system in SDSS J1547. Furthermore, the long-term light curve from CSS can be well described by a sinusoidal function with a periodicity about 2159 d, providing further evidence to support the expected central BBH system in SDSS J1547. Therefore, it is interesting to treat different line profiles of broad Balmer emission lines as intrinsic indicators of central BBH systems in broad line AGN. Under assumptions of BBH systems, 0.125 per cent of broad-line AGN can be expected to have very different line profiles of broad Balmer emission lines. Future study on more broad line AGN with very different line profiles of broad Balmer emission lines could provide further clues on the different line profiles of broad Balmer emission lines as indicator of BBH systems.

scholarly journals The gravitational redshift in the broad line region of the active galactic nucleus Mrk 110

2006 ◽  
Vol 2 (S238) ◽  
pp. 369-370
Author(s):  
N. Gavrilović ◽  
L.Č Popović ◽  
W. Kollatschny
Keyword(s):  
Black Hole ◽  
Gravitational Field ◽  
Active Galactic Nucleus ◽  
Broad Line ◽  
Line Profiles ◽  
Central Black Hole ◽  
Broad Line Region ◽  
Line Region ◽  
Field Influence

AbstractWe used the long term spectroscopic observations of Mrk 110 (Hα and Hβ lines) to investigate the gravitational field influence on spectral line profiles. We found that effects of gravitational field can be measured and that the lines are more intense where the emission is originating close to the central black hole of Mrk 110.

scholarly journals Predicting the broad-lines polarization emitted by supermassive binary black holes

2019 ◽  
Vol 623 ◽  
pp. A56 ◽  
Author(s):  
D. Savić ◽  
F. Marin ◽  
L. Č. Popović
Keyword(s):  
Black Holes ◽  
Emission Lines ◽  
Polarization Angle ◽  
Broad Line ◽  
Line Profiles ◽  
Binary Black Holes ◽  
True Nature ◽  
Line Shapes ◽  
Highly Sensitive ◽  
Balmer Lines

Context. Some Type-1 active galactic nuclei (AGN) show extremely asymmetric Balmer lines with the broad peak redshifted or blueshifted by thousands of km s−1. These AGN may be good candidates for supermassive binary black holes (SMBBHs). The complex line shapes can be due to the complex kinematics of the two broad line regions (BLRs). Therefore other methods should be applied to confirm the SMBBHs. One of them is spectropolarimetry. Aims. We rely on numerical modeling of the polarimetry of binary black holes systems, since polarimetry is highly sensitive to geometry, in order to find the specific influence of supermassive binary black hole (SMBBH) geometry and dynamics on polarized parameters across the broad line profiles. We apply our method to SMBBHs in which both components are assumed to be AGN with distances at the subparsec scale. Methods. We used a Monte Carlo radiative transfer code that simulates the geometry, dynamics, and emission pattern of a binary system where two black holes are getting increasingly close. Each gravitational well is accompanied by its own BLR and the whole system is surrounded by an accretion flow from the distant torus. We examined the emission line deformation and predicted the associated polarization that could be observed. Results. We modeled scattering-induced broad line polarization for various BLR geometries with complex kinematics. We find that the presence of SMBBHs can produce complex polarization angle profiles φ and strongly affect the polarized and unpolarized line profiles. Depending on the phase of the SMBBH, the resulting double-peaked emission lines either show red or blue peak dominance, or both the peaks can have the same intensity. In some cases, the whole line profile appears as a single Gaussian line, hiding the true nature of the source. Conclusions. Our results suggest that future observation with the high resolution spectropolarimetry of optical broad emission lines could play an important role in detecting subparsec SMBBHs.

scholarly journals Near-infrared broad-line profiles in low-redshift QSOs

1992 ◽  
Vol 395 ◽  
pp. 403 ◽  
Author(s):  
Keith L. Thompson
Keyword(s):  
Near Infrared ◽  
Broad Line ◽  
Line Profiles

scholarly journals On the origin of broad line wings in molecular cloud spectra

1991 ◽  
Vol 147 ◽  
pp. 205-209
Author(s):  
Bruce G. Elmegreen
Keyword(s):  
Molecular Cloud ◽  
Realistic Model ◽  
Average Density ◽  
Broad Line ◽  
Line Profiles ◽  
The Core ◽  
Cloud Parameters ◽  
Dense Cores ◽  
Local Average ◽  
Magnetic Waves

The broad line wings in molecular cloud spectra are proposed to result from strong magnetic waves on the periphery of dense cores and in the intercore regions where the Alfvén velocity should be larger than average. The observed line profiles are reproduced by a simple but realistic model, and the ratio of the broad to the narrow line components is found to equal approximately three, independent of cloud parameters, as long as the core/intercore contrast in the local average density is sufficiently large. Interactions between the magnetic waves should produce dense clumps in the non-linear splash regions between converging flows.

Experimental Study of Ion Dynamic Effects in Overlapping Helium Lines at Low Densities

1983 ◽  
Vol 38 (1) ◽  
pp. 37-46 ◽  
Author(s):  
A. Piel ◽  
H. Richter
Keyword(s):  
Experimental Study ◽  
High Purity ◽  
Line Shape ◽  
Plasma Source ◽  
Line Profiles ◽  
Dynamic Effects ◽  
Electron Densities ◽  
Plasma Parameters ◽  
Critical Comparison

Abstract The line profiles of the overlapping helium lines 447.1 nm and 492.2 nm have been investigated in an improved plasma source of high purity at electron densities of 1 × 1021 m−3 and 3 × 1021 m−3 . The plasma parameters Ne, Te and T0 were determined carefully by independent diagnostics, which enables a critical comparison with existing theories (BCS II and MMM). We observed ion dynamic effects which considerably modify the line shape of the forbidden components. Our experiments extend the existing observations towards higher ion temperatures. Systematic trends observed earlier are critically discussed.

scholarly journals Ubiquitous C IV 1550 Variability in B and Be Stars

1987 ◽  
Vol 92 ◽  
pp. 286-288 ◽  
Author(s):  
G. Sonneborn ◽  
M.P. Garhart ◽  
C.A. Grady
Keyword(s):  
Time Scale ◽  
High Dispersion ◽  
Be Stars ◽  
Line Profiles ◽  
Standard Star ◽  
B Stars ◽  
Short And Long Term ◽  
Resonance Transitions ◽  
Long Term Behavior

Studies of line profile variability of the ultraviolet 1550 Angstrom resonance transitions of C IV in Be stars (Sonneborn et al. 1986; Grady, et al. 1986a,b) have prompted an investigation into the short- and long-term behavior of the C IV lines in other types of B stars. We present examples of two well-studied Be stars, Omega Orionis and 66 Ophiuchi, and two non-Be stars, Beta Cephei and the standard star Zeta Cassiopeiae. Zeta Cas is also known to be a 53 Per variable (see Cox 1983). The IUE SWP high-dispersion spectra of Beta Cep and Zeta Cas have been obtained from the IUE archives. It has been known for some years that the C IV line profiles in Beta Cep vary in a time scale of several days (Fishel and Sparks, 1980). However, it came as a surprise to discover C IV variability in Zeta Cas. Available data allow us to set an upper limit of several months for the time scale of Zeta Cas C IV variability. The principal difference between the C IV variability in Be and non-Be stars appears to be the magnitude and velocity range of the effect.

scholarly journals Zodiacal Light - Scattered Fraunhofer Line Profiles

1996 ◽  
Vol 150 ◽  
pp. 337-340
Author(s):  
David Clarke
Keyword(s):  
Line Shape ◽  
Brightness Variation ◽  
Line Profiles ◽  
Scattering Function ◽  
Zodiacal Light ◽  
Successful Model ◽  
Fraunhofer Line ◽  
Shape Changes

AbstractThe scattering function of Hong's successful model for the brightness variation with elongation, B(ε), of the Zodiacal Light has been used to calculate profiles of Doppler shifted Fraunhofer lines. Substantial line shape changes with ε are predicted with an indication of a bifurcation at ε < 30°, so offering an explanation for reported F corona observations.

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