scholarly journals Testing the relativistic Doppler boost hypothesis for supermassive binary black holes candidates via broad emission line profiles

2019 ◽  
Vol 491 (3) ◽  
pp. 4023-4030 ◽  
Author(s):  
Zihao Song ◽  
Junqiang Ge ◽  
Youjun Lu ◽  
Xiang Ji
Keyword(s):  
Black Holes ◽  
Emission Lines ◽  
Binary Black Holes ◽  
Broad Emission ◽  
Line Region ◽  
Two Samples ◽  
Region Model ◽  
Orbital Orientation ◽  
The Continuum

ABSTRACT Optical periodicity QSOs found by transient surveys are suggested to be subparsec supermassive binary black holes (BBHs). An intriguing interpretation for the periodicity of some of those QSOs is that the continuum is radiated from the accretion disc associated with the BBH secondary component and modulated by the periodical rotation of the secondary via Doppler-boost effect. Close to edge-on orbital orientation can lead to more significant Doppler-boost effect and thus are preferred for these systems, which is distinct from those normal type-1 QSOs with more or less face-on orientations. Therefore, the profiles of broad lines emitted from these Doppler-modulated systems may be significantly different from other systems that are not Doppler modulated. We investigate the properties of the broad emission lines of optical-periodicity QSOs, including both a sample of QSOs that can be interpreted by the Doppler-modulated effects and a sample that cannot. We find that there is no obvious difference in the profiles and other properties of various (stacked) broad emission lines of these two samples, though a simple broad line region model would suggest significant differences. Our finding raises a challenge to the Doppler boost hypothesis for some of those BBHs candidates with optical periodicity.

scholarly journals Microlensing Induced Spectral Variability In Q2237+0305

1996 ◽  
Vol 173 ◽  
pp. 241-246
Author(s):  
Geraint F. Lewis ◽  
Mike J. Irwin ◽  
Paul C. Hewett
Keyword(s):  
Emission Line ◽  
Line Emission ◽  
Emission Lines ◽  
Broad Line ◽  
Spectral Variability ◽  
Broad Emission ◽  
Quasar Spectra ◽  
Line Region ◽  
Broad Emission Line ◽  
The Continuum

The degree of microlensing induced amplification is dependent upon the size of a source. As quasar spectra consist of the sum of emission from different regions this scale dependent amplification can produce spectral differences between the images of a macrolensed quasar. This paper presents the first direct spectroscopic evidence for this effect, providing a limit on the scale of the continuum and the broad line emission regions at the center of a source quasar (2237+0305). Lack of centroid and profile differences in the emission lines indicate that substructure in the broad emission line region is > 0.05 parsecs.

scholarly journals Variation of Broad Emission Lines from QSOs with Optical/UV Periodicity to Test the Interpretation of Supermassive Binary Black Holes

2021 ◽  
Vol 910 (2) ◽  
pp. 101
Author(s):  
Xiang Ji ◽  
Youjun Lu ◽  
Junqiang Ge ◽  
Changshuo Yan ◽  
Zihao Song
Keyword(s):  
Black Holes ◽  
Emission Lines ◽  
Binary Black Holes ◽  
Broad Emission

The DIVING3D Project: Analysis of the nuclear region of Early-type Galaxies

2020 ◽  
Vol 15 (S359) ◽  
pp. 454-456
Author(s):  
T. V. Ricci ◽  
J. E. Steiner ◽  
R. B. Menezes
Keyword(s):  
Emission Lines ◽  
H Ii Regions ◽  
Sample Type ◽  
Early Type ◽  
Integral Field Spectroscopy ◽  
Project Analysis ◽  
Line Region ◽  
Field Unit ◽  
Integral Field

AbstractIn this work, we present preliminary results regarding the nuclear emission lines of a statistically complete sample of 56 early-type galaxies that are part of the Deep Integral Field Spectroscopy View of Nuclei of Galaxies (DIVING3D) Project. All early type galaxies (ETGs) were observed with the Gemini Multi-Object Spectrograph Integral Field Unit (GMOS-IFU) installed on the Gemini South Telescope. We detected emission lines in 93% of the sample, mostly low-ionization nuclear emission-line region galaxies (LINERs). We did not find Transition Objects nor H II regions in the sample. Type 1 objects are seen in ∼23% of the galaxies.

scholarly journals Exploring the link between C IV outflow kinematics and sublimation-temperature dust in quasars

2020 ◽  
Author(s):  
Matthew J Temple ◽  
Manda Banerji ◽  
Paul C Hewett ◽  
Amy L Rankine ◽  
Gordon T Richards
Keyword(s):  
Emission Line ◽  
High Frequency ◽  
Infrared Emission ◽  
Black Hole Mass ◽  
Sublimation Temperature ◽  
Continuum Source ◽  
Broad Emission ◽  
Line Region ◽  
Using Data

Abstract Using data from SDSS, UKIDSS and WISE, we investigate the properties of the high-frequency cutoff to the infrared emission in ≃5000 carefully selected luminous (Lbol ∼ 1047) type 1 quasars. The strength of ≃2 μm emission, corresponding to emission from the hottest ($T>1200\rm \, K$) dust in the sublimation zone surrounding the central continuum source, is observed to correlate with the blueshift of the C iv λ1550 emission line. We therefore find that objects with stronger signatures of nuclear outflows tend to have a larger covering fraction of sublimation-temperature dust. When controlling for the observed outflow strength, the hot dust covering fraction does not vary significantly across our sample as a function of luminosity, black hole mass or Eddington fraction. The correlation between the hot dust and the C iv line blueshifts, together with the lack of correlation between the hot dust and other parameters, therefore provides evidence of a link between the properties of the broad emission line region and the infrared-emitting dusty regions in quasars.

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 The broad line region of AGN: Kinematics and physics

2006 ◽  
pp. 1-11 ◽  
Author(s):  
L.C. Popovic
Keyword(s):  
Electron Temperature ◽  
Accretion Disk ◽  
Emission Lines ◽  
Physical Parameters ◽  
Broad Line ◽  
Physical Conditions ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region

In this paper a discussion of kinematics and physics of the Broad Line Region (BLR) is given. The possible physical conditions in the BLR and problems in determination of the physical parameters (electron temperature and density) are considered. Moreover, one analyses the geometry of the BLR and the probability that (at least) a fraction of the radiation in the Broad Emission Lines (BELs) originates from a relativistic accretion disk.

scholarly journals Variability of NGC 3783: First Results from an Intensive Ground-Based Monitoring Campaign

1994 ◽  
Vol 159 ◽  
pp. 407-407
Author(s):  
Giovanna M. Stirpe
Keyword(s):  
Emission Lines ◽  
Intensive Monitoring ◽  
Monitoring Campaign ◽  
Broad Emission ◽  
Photometric Observations ◽  
First Results ◽  
The Continuum

The International AGN Watch collaboration undertook an intensive monitoring campaign of the bright Seyfert 1 galaxy NGC 3783 between December 1991 and August 1992, in order to study the variations of the continuum and broad emission lines. Spectroscopic and photometric observations took place at several ground-based observatories and formed the optical/IR counterpart to the UV observations conducted with the IUE (Reichert et al. 1993).

scholarly journals The polarized signal from broad emission lines in AGNs

2019 ◽  
Vol 491 (1) ◽  
pp. 1-12 ◽  
Author(s):  
P Lira ◽  
R W Goosmann ◽  
M Kishimoto ◽  
R Cartier
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Position Angle ◽  
Emission Lines ◽  
Type I ◽  
Line Profiles ◽  
Scattering Media ◽  
Broad Emission ◽  
Line Region ◽  
Scattering Signal

ABSTRACT Using the stokes Monte Carlo radiative transfer code, we revisit the predictions of the spectropolarimetric signal from a disc-like broad emission line region (BLR) in type I active galactic nuclei due to equatorial scattering. We reproduce the findings of previous works, but only for a scatterer that is much more optically and geometrically thick than previously proposed. We also find that when taking into account the polarized emission from all regions of the scatterer, the swing of the polarization position angle (PA) is in the opposite direction to that originally proposed. Furthermore, we find that the presence of outflows in the scattering media can significantly change the observed line profiles, with the PA of the scattering signal being enhanced in the presence of radially outflowing winds. Finally, a characteristically different PA profile, shaped like an ‘M’, is seen when the scatterer is co-spatial with the BLR and radially outflowing.

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