Infrared Line Shapes in Active Galactic Nuclei

AbstractLine profiles can provide fundamental information on the physics of active galactic nuclei (AGN). In the case of narrow-line Seyfert 1 galaxies (NLS1s) this is of particular importance since past studies revealed how their permitted line profiles are well reproduced by a Lorentzian function instead of a Gaussian. This has been explained with different properties of the broad-line region (BLR), which may present more pronounced turbulent motions in NLS1s with respect to other AGN. We investigated the line profiles in a recent large NLS1 sample classified using SDSS, and we divided the sources into two subsamples according to their line shapes, Gaussian or Lorentzian. The line profiles seem to separate all the properties of NLS1s. Black hole mass, Eddington ratio, [OIII] luminosity, and Fe II strength are all very different in the Lorentzian and Gaussian samples, as well as their position on the quasar main sequence. We interpret this in terms of evolution within the class of NLS1s. The Lorentzian sources may be the youngest objects, while Gaussian profiles may be typically associated to more evolved objects. Further detailed spectroscopic studies are needed to fully confirm our hypothesis.

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Infrared Line Shapes in Active Galactic Nuclei

Symposium - International Astronomical Union ◽

10.1017/s0074180900176430 ◽

1994 ◽

Vol 159 ◽

pp. 462-462

Author(s):

Rodger I. Thompson

Keyword(s):

Active Galactic Nuclei ◽

Electron Density ◽

Galactic Nuclei ◽

Complete Spectrum ◽

Line Shapes ◽

Ngc 4151

This paper presents the complete spectrum of NGC 4151 from 0.87 to 2.5 μm as well as detail of the Paschen α profile in 3C273 at a resolution of about 5000. Analysis of the several observed Fe II lines yields a most probable electron density of 104 and a most likely temperature of 104. The Fe II to H ratio is 2+/− 1 × 10−6 which is 5–7% of the available iron if the Fe/H ratio is solar.

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Influence of Black Hole Spin on the Shape of the Fe Kα Spectral Line: The Case of 3C 405

Open Astronomy ◽

10.1515/astro-2017-0321 ◽

2011 ◽

Vol 20 (3) ◽

Author(s):

P. Jovanović ◽

V. Borka Jovanović ◽

D. Borka

Keyword(s):

Black Holes ◽

Black Hole ◽

Active Galactic Nuclei ◽

Accretion Disks ◽

Galactic Nuclei ◽

Kerr Metric ◽

Line Shapes ◽

Cygnus A ◽

Angular Momenta ◽

Innermost Region

AbstractHere we analyze how the angular momenta (spins) of black holes in the centers of Active Galactic Nuclei (AGN) affect the shape of the FeK line emitted from their accretion disks. For that purpose, we compared the observed line profile in the case of radio galaxy 3C 405 (Cygnus A) with its profiles, obtained by numerical simulations based on ray-tracing method in the Kerr metric. Our results show that the spins of rotating central black holes of AGN have significant influence on their FeKα line shapes. Also, we found that in the case of Cygnus A the observed line is probably emitted from the innermost region of its slightly inclined accretion disk around very slowly rotating or even stationary central black hole.

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Kinematic signatures of reverberation mapping of close binaries of supermassive black holes in active galactic nuclei

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936398 ◽

2020 ◽

Vol 635 ◽

pp. A1 ◽

Cited By ~ 6

Author(s):

Andjelka B. Kovačević ◽

Jian-Min Wang ◽

Luka Č. Popović

Keyword(s):

Black Holes ◽

Active Galactic Nuclei ◽

Transfer Functions ◽

Galactic Nuclei ◽

Supermassive Black Holes ◽

Close Binary ◽

Broad Line ◽

Line Profiles ◽

Reverberation Mapping ◽

Line Shapes

Context. An unresolved region in the relative vicinity of the event horizon of a supermassive black holes (SMBH) in active galactic nuclei (AGN) radiates strongly variable optical continuum and broad-line emission flux. These fluxes can be processed into two-dimensional transfer functions (2DTF) of material flows that encrypt various information about these unresolved structures. An intense search for kinematic signatures of reverberation mapping of close binary SMBH (SMBBH) is currently ongoing. Aims. Elliptical SMBBH systems (i.e. both orbits and disc-like broad-line regions (BLR) are elliptic) have not been assessed in 2DTF studies. We aim to numerically infer such a 2DTF because the geometry of the unresolved region is imprinted on their optical emission. Through this, we determine their specific kinematical signatures. Methods. We simulated the geometry and kinematics of SMBBH whose components are on elliptical orbits. Each SMBH had a disc-like elliptical BLR. The SMBHs were active and orbited each other tightly at a subparsec distance. Results. Here we calculate for the first time 2DTF, as defined in the velocity-time delay plane, for several elliptical configurations of SMBBH orbits and their BLRs. We find that these very complex configurations are clearly resolved in maps. These results are distinct from those obtained from circular and disc-wind geometry. We calculate the expected line variability for all SMBBH configurations. We show that the line shapes are influenced by the orbital phase of the SMBBH. Some line profiles resemble observed profiles, but they can also be much deformed to look like those from the disc-wind model. Conclusions. First, our results imply that using our 2DTF, we can detect and quantify kinematic signatures of elliptical SMBBH. Second, the calculated expected line profiles share some intriguing similarities with observed profiles, but also with some profiles that are synthesised in disc-wind models. To overcome the non-uniqueness of the spectral line shapes as markers of SMBBH, they must be accompanied with 2DTF.

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5.9. Gas dynamics in the central part of the Sy 1 galaxies: III Zw 2 and Mrk 817

Symposium - International Astronomical Union ◽

10.1017/s0074180900084710 ◽

1998 ◽

Vol 184 ◽

pp. 227-228

Author(s):

L. Č. Popović ◽

I. Vince ◽

A. Kubičela ◽

S. Salim

Keyword(s):

Active Galactic Nuclei ◽

Gas Dynamics ◽

Galactic Nuclei ◽

Active Galaxies ◽

Line Shapes

Spectra of Active Galactic Nuclei (AGN) indicate that in their central parts a composite motion of emission gas exists. An analysis of broad as well as narrow lines of active galaxies can give information about gas dynamics in central part of these objects (see e.g. Netzer 1990, Osterbrock 1990). Here we present the investigation of the Hβ and O III[4959,5007] line shapes of the two Sy 1 galaxis: Mrk 817 and III Zw2.

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On the Time Scales of Optical Variability of AGN and the Shape of Their Optical Emission Line Profiles

Atoms ◽

10.3390/atoms7010026 ◽

2019 ◽

Vol 7 (1) ◽

pp. 26

Author(s):

Edi Bon ◽

Paola Marziani ◽

Predrag Jovanović ◽

Nataša Bon

Keyword(s):

Emission Line ◽

Active Galactic Nuclei ◽

Time Scales ◽

Accretion Disks ◽

Galactic Nuclei ◽

Optical Emission ◽

Light Curves ◽

Optical Variability ◽

Line Profiles ◽

Line Shapes

The mechanism of the optical variability of active galactic nuclei (AGN) is still very puzzling. It is now widely accepted that the optical variability of AGN is stochastic, producing red noise-like light curves. In case they were to be periodic or quasi-periodic, one should expect that the time scales of optical AGN variability should relate to orbiting time scales of regions inside the accretion disks with temperatures mainly emitting the light in this wavelength range. Knowing the reverberation scales and masses of AGN, expected orbiting time scales are in the order of decades. Unfortunately, most of monitored AGN light curves are not long enough to investigate such time scales of periodicity. Here we investigate the AGN optical variability time scales and their possible connections with the broad emission line shapes.

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Spectral Monitoring of AGN: Preliminary Results for Ark 564 and Arp 102B

Open Astronomy ◽

10.1515/astro-2017-0323 ◽

2011 ◽

Vol 20 (3) ◽

Author(s):

A. I. Shapovalova ◽

L. Č. Popović ◽

D. Ilić ◽

A. Kovačević ◽

J. Kovačević ◽

...

Keyword(s):

Active Galactic Nuclei ◽

Radio Galaxy ◽

Galactic Nuclei ◽

Optical Emission ◽

Emission Lines ◽

Broad Line ◽

Preliminary Results ◽

Line Shapes ◽

Spectral Monitoring

AbstractWe present preliminary results of the long-term spectral monitoring of two active galactic nuclei with different broad line shapes: Ark 564 and Arp 102B. Ark 564 is a bright nearby narrow-line Syfert 1 (NLS1) galaxy with relatively narrow permitted optical emission lines and a high Fe II/Hβ ratio, while Arp 102B is a nearby broad-line radio galaxy with broad double-peaked Balmer emission lines. The spectra of Ark 564 were observed during 11-year period (1999-2009) and the spectra of Arp 102B in the 12-year period (1998-2009), with SAO 6 m and 1 m telescopes (Russia) and the OAGH 2.1 m telescope (Cananea, Mexico).

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