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 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.

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 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.

scholarly journals LLAMA: The MBH–σ⋆ relation of the most luminous local AGNs

2020 ◽  
Vol 634 ◽  
pp. A114 ◽  
Author(s):  
Turgay Caglar ◽  
Leonard Burtscher ◽  
Bernhard Brandl ◽  
Jarle Brinchmann ◽  
Richard I. Davies ◽  
...  
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Velocity Dispersion ◽  
Signal To Noise Ratio ◽  
Broad Line ◽  
Host Galaxies ◽  
Spatially Resolved ◽  
Stellar Velocity ◽  
Black Hole Masses

Context. The MBH–σ⋆ relation is considered a result of coevolution between the host galaxies and their supermassive black holes. For elliptical bulge hosting inactive galaxies, this relation is well established, but there is still discussion concerning whether active galaxies follow the same relation. Aims. In this paper, we estimate black hole masses for a sample of 19 local luminous active galactic nuclei (AGNs; LLAMA) to test their location on the MBH–σ⋆ relation. In addition, we test how robustly we can determine the stellar velocity dispersion in the presence of an AGN continuum and AGN emission lines, and as a function of signal-to-noise ratio. Methods. Supermassive black hole masses (MBH) were derived from the broad-line-based relations for Hα, Hβ, and Paβ emission line profiles for Type 1 AGNs. We compared the bulge stellar velocity dispersion (σ⋆) as determined from the Ca II triplet (CaT) with the dispersion measured from the near-infrared CO (2-0) absorption features for each AGN and find them to be consistent with each other. We applied an extinction correction to the observed broad-line fluxes and we corrected the stellar velocity dispersion by an average rotation contribution as determined from spatially resolved stellar kinematic maps. Results. The Hα-based black hole masses of our sample of AGNs were estimated in the range 6.34 ≤ log MBH ≤ 7.75 M⊙ and the σ⋆CaT estimates range between 73 ≤ σ⋆CaT ≤ 227 km s−1. From the so-constructed MBH − σ⋆ relation for our Type 1 AGNs, we estimate the black hole masses for the Type 2 AGNs and the inactive galaxies in our sample. Conclusions. We find that our sample of local luminous AGNs is consistent with the MBH–σ⋆ relation of lower luminosity AGNs and inactive galaxies, after correcting for dust extinction and the rotational contribution to the stellar velocity dispersion.

scholarly journals Observations of Quasar Broad-Line Profiles in the Optical and Infrared

1989 ◽  
Vol 134 ◽  
pp. 133-134
Author(s):  
Keith Louis Thompson
Keyword(s):  
Broad Line ◽  
Line Profiles ◽  
Grating Spectrometer ◽  
Optical Wavelengths

Seven low redshift QSOs have been observed spectroscopically at infrared and optical wavelengths at McDonald Observatory. The two instruments used were the infrared grating spectrometer (IRGS; see Lester, Harvey, and Carr 1988 for a description) on the 2.7m reflector, and the es-2 cassegrain spectrometer on the 2.1m. Table 1 shows the objects and spectra taken.

scholarly journals Shock fronts in the long GRB031203 host galaxy

2019 ◽  
Vol 488 (4) ◽  
pp. 4487-4496 ◽  
Author(s):  
M Contini
Keyword(s):  
Line Profile ◽  
Host Galaxy ◽  
Broad Line ◽  
Line Profiles ◽  
Internal Edge ◽  
Detailed Modelling ◽  
Coupled Effect ◽  
Shock Fronts

ABSTRACT The detailed modelling of the spectra observed from the long GRB031203 host galaxy at different epochs during the 2003–2009 yr is presented. The line profiles show FWHM of ∼100 $\rm km\, s^{-1}$. A broad-line profile with FWHM ≤ 400 $\rm km\, s^{-1}$ appears in the line sockets from the 2009 observations. We suggest that the narrow lines show the velocity of starburst (SB) debris, while the broad ones are due to the wind from SB stars. The spectra are emitted from the gas downstream of different shock fronts which are at work on the edges of the emitting clouds. A head-on-back shock appears when the wind from the SB stars reaches the internal edge of the SB debris moving outwards. A head-on shock is created by collision of the debris with the ISM clouds. Line ratios in both cases are calculated by the coupled effect of shock and photoionization from the SB. The models selected by fitting the calculated to the observed line ratios show that the ionization parameters, the shock velocities and the gas pre-shock densities slowly decrease with time. Oxygen metallicities (12+log(O/H) = 8.3–8.48) are lower than solar (8.82) by a factor <3 and nitrogen metallicities are lower than solar (12 + log(N/H)  = 8.0, Grevesse & Sauval) by factors of 3–5.

scholarly journals The Structure of the Envelopes of Symbiotic Novae

1990 ◽  
Vol 122 ◽  
pp. 431-432
Author(s):  
G.B. Baratta ◽  
A. Damineli Neto ◽  
C. Rossi ◽  
R. Viotti
Keyword(s):  
High Resolution ◽  
Uv Spectra ◽  
Emission Lines ◽  
Broad Line ◽  
Line Profiles ◽  
Composite Spectrum ◽  
Multiple Structure ◽  
Broad Emission ◽  
Light History

Symbiotic novae are composite spectrum stars whose light history is characterized by one single major outburst. At high resolution their optical and UV spectra are very rich of emission lines belonging to a wide ionization range. Generally one can identify both narrow and broad line systems. The latter includes emission lines with multiple structure, broad emission wings, WR features, and P Cygnl lines. Frequently the broad line profiles are largely variable with time. They should be associated with the major stellar outburst. An overview of the problem with extensive references can be found in Viotti (1989).

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.

scholarly journals Velocity-Resolved Echo Mapping

1997 ◽  
Vol 159 ◽  
pp. 146-150
Author(s):  
K. Horne
Keyword(s):  
Emission Line ◽  
Free Fall ◽  
Approximate Symmetry ◽  
Broad Line ◽  
Line Profiles ◽  
Ngc 4151 ◽  
The Continuum

AbstractWe probe the structure and kinematics of Seyfert broad-line regions by using a velocity-delay map to fit simultaneously the observed variations in the continuum and the emission-line profiles. The velocity-delay map of C IVλ1550 emission constructed from 44 IUE spectra of NGC 4151 suggests virial motions, with 107M⊙ inside two light days. Pure inflow and outflow kinematics are ruled out by the approximate symmetry of the map. A stronger redshifted response at small delays suggests either a component with free-fall kinematics, or an outflow with CIV being emitted inward by optically thick gas clouds.

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