scholarly journals FeII, FeI Emission Lines from Accretion Disks: An Explanation for “FeII Problem” in AGNs?

1994 ◽  
Vol 159 ◽  
pp. 463-463
Author(s):  
Chunyan Wei ◽  
Fuzhen Cheng ◽  
Junhan You
Keyword(s):  
Active Galactic Nuclei ◽  
Accretion Disk ◽  
Accretion Disks ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
Broad Line ◽  
Broad Line Region ◽  
Line Region

For the solution of the puzzling “FeII problem” in active galactic nuclei(AGNs) (Netzer et al. 1983; Wills et al. 1985), we pay our attention to optical band and suggest: (1)the observed so-called “FeII emission lines” features may be blending of FeII multiples and FeI multiples. Our previous work(Wei et al. 1993) has showed that there are many FeI emission lines whose wavelength lie around the observed “FeII emission lines” features. In fact, FeI emission lines have been observed in the spectrum of PHL 1092(Bergeron et al. 1980; Cheng et al. 1993). (2)the emission lines from accretion disk must be considered besides the emission from broad line region.

scholarly journals The role of failed accretion disk winds in active galactic nuclei

2019 ◽  
Vol 15 (S356) ◽  
pp. 82-86 ◽  
Author(s):  
Margherita Giustini ◽  
Daniel Proga
Keyword(s):  
Active Galactic Nuclei ◽  
Accretion Disks ◽  
Galactic Nuclei ◽  
Broad Line ◽  
X Ray ◽  
Broad Line Region ◽  
Line Region ◽  
Gravitational Pull ◽  
Theoretical Evidence

AbstractBoth observational and theoretical evidence point at outflows originating from accretion disks as fundamental ingredients of active galactic nuclei (AGN). These outflows can have more than one component, for example an unbound supersonic wind and a failed wind (FW). The latter is a prediction of the simulations of radiation-driven disk outflows which show that the former is accompanied by an inner failed component, where the flow struggles to escape from the strong gravitational pull of the supermassive black hole. This FW component could provide a physical framework to interpret various phenomenological components of AGN. Here we briefly discuss a few of them: the broad line region, the X-ray obscurer, and the X-ray corona.

scholarly journals Accretion in the broad line region of active galactic nuclei

2006 ◽  
Vol 2 (S238) ◽  
pp. 329-330
Author(s):  
E. Bon ◽  
L. Č. Popović ◽  
D. Ilić
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
Broad Line ◽  
Line Profiles ◽  
Spherical Region ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region ◽  
Two Component

AbstractWe modeled the single-peaked Broad Emission Lines (BELs) with two-component model (accretion disk, with surrounding spherical region), comparing it with observational line profiles for a number of Active Galactic Nuclei (AGN). We find that the accretion in the Broad Line Region (BLR) can be present even if the profiles of BELs are single-peaked.

Rejection of the Binary Broad‐Line Region Interpretation of Double‐peaked Emission Lines in Three Active Galactic Nuclei

1997 ◽  
Vol 490 (1) ◽  
pp. 216-226 ◽  
Author(s):  
Michael Eracleous ◽  
Jules P. Halpern ◽  
Andrea M. Gilbert ◽  
Jeffrey A. Newman ◽  
Alexei V. Filippenko
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Emission Lines ◽  
Broad Line ◽  
Broad Line Region ◽  
Line Region

scholarly journals Analyzing temporal variations of AGN emission line profiles in the context of (dusty) cloud structure formation in the broad line region

2019 ◽  
Vol 621 ◽  
pp. A46 ◽  
Author(s):  
J. Esser ◽  
J.-U. Pott ◽  
H. Landt ◽  
W. D. Vacca
Keyword(s):  
Active Galactic Nuclei ◽  
Accretion Disk ◽  
Galactic Nuclei ◽  
Temporal Variations ◽  
Cloud Formation ◽  
Broad Line ◽  
Ngc 4151 ◽  
Broad Line Region ◽  
The Past ◽  
Line Region

The formation processes and the exact appearance of the dust torus and broad line region (BLR) of active galactic nuclei (AGN) are under debate. Theoretical studies show a possible connection between the dust torus and BLR through a common origin in the accretion disk. However observationally the dust torus and BLR are typically studied separately. NGC 4151 is possibly one of the best suited Seyfert 1 galaxies for simultaneous examinations because of its high number of both photometric and spectroscopic observations in the past. Here we compare changes of the dust radius to shape variations of broad emission lines (BEL). While the radius of the dust torus decreased by almost a factor of two from 2004 to 2006 shape variations can be seen in the red wing of BELs of NGC 4151. These simultaneous changes are discussed in a dust and BEL formation scheme. We also use the BEL shape variations to assess possible cloud distributions, especially in azimuthal direction, which could be responsible for the observed variations. Our findings can best be explained in the framework of a dust inflated accretion disk. The changes in the BELs suggest that this dusty cloud formation does not happen continuously, and over the whole accretion disk, but on the contrary in spatially confined areas over rather short amount of times. We derive limits to the azimuthal extension of the observed localized BEL flux enhancement event.

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