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 Dusty origin of the Broad Line Region in active galaxies

2012 ◽  
Vol 8 (S290) ◽  
pp. 21-24
Author(s):  
Bozena Czerny ◽  
Krzysztof Hryniewicz ◽  
Janusz Kaluzny ◽  
Ishita Maity
Keyword(s):  
Black Hole ◽  
Active Galaxies ◽  
Emission Lines ◽  
Broad Line ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region ◽  
Interesting Possibility ◽  
Considerable Complexity

AbstractThe most characteristic property of active galaxies, including quasars, are prominent broad emission lines. I will discuss an interesting possibility that dust is responsible for this phenomenon. The dust is known to be present in quasars in the form of a dusty/molecular torus which results in complexity of the appearance of active galaxies. However, this dust is located further from the black hole than the Broad Line Region. We propose that the dust is present also closer in and it is actually responsible for formation of the broad emission lines. The argument is based on determination of the temperature of the disk atmosphere underlying the Broad Line Region: it is close to 1000 K, independently from the black hole mass and accretion rate of the object. The mechanism is simple and universal but leads to a considerable complexity of the active nucleus surrounding. The understanding the formation of BLR opens a way to use it reliably - in combination with reverberation measurement of its size - as standard candles in cosmology.

A Photoionization Method for Estimating Black Hole Masses in Quasars

2018 ◽  
Vol 14 (S342) ◽  
pp. 270-271
Author(s):  
C. Alenka Negrete ◽  
Deborah Dultzin ◽  
Paola Marziani ◽  
Jack W. Sulentic ◽  
M. L. Martínez-Aldama
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
Broad Line ◽  
Reverberation Mapping ◽  
Physical Conditions ◽  
Broad Line Region ◽  
Supermassive Black Hole ◽  
Line Region ◽  
Black Hole Masses

AbstractWe present a method that uses photoionization codes (CLOUDY) to estimate the supermassive black hole masses (MBH) for quasars at low and high redshift. This method is based on the determination of the physical conditions of the broad line region (BLR) using observational diagnostic diagrams from line ratios in the UV. We also considered that the density and metallicity of the BLR in quasars at high z could be different from those at the nearby Universe. The computed black hole masses obtained using this method are in agreement with those derived from the method of reverberation mapping.

scholarly journals A Survey of QSO Emission Lines

1986 ◽  
Vol 119 ◽  
pp. 279-288
Author(s):  
Beverley J. Wills
Keyword(s):  
Black Hole ◽  
Good Description ◽  
Emission Lines ◽  
Broad Line ◽  
Physical Conditions ◽  
Broad Line Region ◽  
Heating Mechanism ◽  
Ionization Density ◽  
Line Region ◽  
High Temperature Gas

“Standard” photoionization models of the broad line region (BLR) consist of numerous small optically thick clouds of identical ionization, density, temperature and optical depth, moving under the influence of the gravity and radiation field of a 107–8 M⊙ black hole and confined by a high temperature gas. Such models have provided a good description of observed line strengths and widths with only very minor modification. Although photoionization remains the most important heating mechanism in the BLR, new observations point to a wider range of physical conditions and to clues about the geometric and dynamic arrangement of the emitting gas. I want to highlight the observations that have led us to this view.

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 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.

scholarly journals MICROLENSING OF QUASAR BROAD EMISSION LINES: CONSTRAINTS ON BROAD LINE REGION SIZE

2013 ◽  
Vol 764 (2) ◽  
pp. 160 ◽  
Author(s):  
E. Guerras ◽  
E. Mediavilla ◽  
J. Jimenez-Vicente ◽  
C. S. Kochanek ◽  
J. A. Muñoz ◽  
...  
Keyword(s):  
Emission Lines ◽  
Broad Line ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region ◽  
Region Size

scholarly journals Microlensing of the broad emission lines in 27 gravitationally lensed quasars. Broad line region structure and kinematics

2021 ◽  
Author(s):  
C. Fian ◽  
E. Mediavilla ◽  
V. Motta ◽  
J. Jiménez-Vicente ◽  
J. A. Muñoz ◽  
...  
Keyword(s):  
Emission Lines ◽  
Broad Line ◽  
Broad Line Region ◽  
Broad Emission ◽  
Line Region
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