scholarly journals A NEW METHOD TO OBTAIN THE BROAD LINE REGION SIZE OF HIGH REDSHIFT QUASARS

2014 ◽  
Vol 794 (1) ◽  
pp. 95 ◽  
Author(s):  
C. Alenka Negrete ◽  
Deborah Dultzin ◽  
Paola Marziani ◽  
Jack W. Sulentic
Keyword(s):  
High Redshift ◽  
New Method ◽  
Broad Line ◽  
Broad Line Region ◽  
Line Region ◽  
Region Size

scholarly journals High-Redshift Quasar Monitoring Campaign: Preliminary Results

2009 ◽  
Vol 5 (S267) ◽  
pp. 198-198 ◽  
Author(s):  
Ismael Botti ◽  
Paulina Lira ◽  
Hagai Netzer ◽  
Shai Kaspi
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
Broad Line ◽  
Black Hole Mass ◽  
High Luminosity ◽  
Monitoring Campaign ◽  
Reverberation Mapping ◽  
Broad Line Region ◽  
Line Region ◽  
Region Size

AbstractWe present a monitoring campaign on high-luminosity quasars which will extend the existing reverberation mapping results by two orders of magnitude in luminosity, probing the broad-line region size and black hole mass of luminous AGN at redshift ~ 2 – 3.

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 Modelling the AGN broad-line region using single-epoch spectra − II. Nearby AGNs

2020 ◽  
Vol 493 (1) ◽  
pp. 1227-1248 ◽  
Author(s):  
S I Raimundo ◽  
M Vestergaard ◽  
M R Goad ◽  
C J Grier ◽  
P R Williams ◽  
...  
Keyword(s):  
Physical Model ◽  
Galaxy Evolution ◽  
High Redshift ◽  
Cost Effective ◽  
Monitoring Data ◽  
Broad Line ◽  
Reverberation Mapping ◽  
Broad Line Region ◽  
Line Region ◽  
Single Epoch

ABSTRACT The structure of the broad-line region (BLR) is an essential ingredient in the determination of active galactic nucleus (AGN) virial black hole masses, which in turn are important to study the role of black holes in galaxy evolution. Constraints on the BLR geometry and dynamics can be obtained from velocity-resolved studies using reverberation mapping data (i.e. monitoring data). However, monitoring data are observationally expensive and only available for a limited sample of AGNs, mostly confined to the local Universe. Here, we explore a new version of a Bayesian inference, physical model of the BLR that uses an individual spectrum and prior information on the BLR size from the radius–luminosity relation, to model the AGN BLR geometry and dynamics. We apply our model to a sample of 11 AGNs, which have been previously modelled using monitoring data. Our single-epoch BLR model is able to constrain some of the BLR parameters with inferred parameter values that agree within the uncertainties with those determined from the modelling of monitoring data. We find that our model is able to derive stronger constraints on the BLR for AGNs with broad emission lines that qualitatively have more substructure and more asymmetry, presumably as they contain more information to constrain the physical model. The performance of this model makes it a practical and cost-effective tool to determine some of the BLR properties of a large sample of low- and high-redshift AGNs, for which monitoring data are not available.

scholarly journals Is the Broad-Line Region Expanding?

1997 ◽  
Vol 159 ◽  
pp. 222-223
Author(s):  
Kan Liang ◽  
Xiang-Tao He ◽  
Zhong-min Wang ◽  
Jun-Han You
Keyword(s):  
High Resolution ◽  
Emission Line ◽  
High Redshift ◽  
Optical Observations ◽  
Broad Line ◽  
Broad Absorption ◽  
Broad Line Region ◽  
Line Region ◽  
Radial Outflow ◽  
Almost All

We suggest that the broad-line regions (BLRs) of QSOs with broad emissionlines (BALs) are expanding, i.e., the clouds are undergoing radial outflow, as illustrated simply in Fig. 1. At least the following observational facts can be explained: 1.Optical observations show that some moderate and high-redshift QSOs have BALs. The number of these QSOs is about 3–10% of all QSOs (Foltz et al. 1990). One can see in Fig. 2 that very low-redshift QSOs have no BALs.2.Almost all BAL QSOs exhibit zabs < zem.3.High-resolution observations reveal that the widths of the broad absorption lines are narrower than that of the corresponding emission line for all BAL QSOs, i.e. Δλ ab < Δλ em.

scholarly journals Measurement of the Broad-Line Region Size in Two Bright Quasars

1996 ◽  
Vol 471 (2) ◽  
pp. L75-L78 ◽  
Author(s):  
Shai Kaspi ◽  
Paul S. Smith ◽  
Dan Maoz ◽  
Hagai Netzer ◽  
Buell T. Jannuzi
Keyword(s):  
Broad Line ◽  
Broad Line Region ◽  
Line Region ◽  
Region Size

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 MEASUREMENT OF THE BROAD-LINE REGION SIZE IN A LUMINOUS MACHO QUASAR

2012 ◽  
Vol 750 (2) ◽  
pp. L43 ◽  
Author(s):  
Doron Chelouche ◽  
Eliran Daniel ◽  
Shai Kaspi
Keyword(s):  
Broad Line ◽  
Broad Line Region ◽  
Line Region ◽  
Region Size

scholarly journals The Relationship between Luminosity and Broad‐Line Region Size in Active Galactic Nuclei

2005 ◽  
Vol 629 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Shai Kaspi ◽  
Dan Maoz ◽  
Hagai Netzer ◽  
Bradley M. Peterson ◽  
Marianne Vestergaard ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Broad Line ◽  
Broad Line Region ◽  
Line Region ◽  
The Relationship ◽  
Region Size

scholarly journals Modelling the AGN broad line region using single-epoch spectra – I. The test case of Arp 151

2019 ◽  
Vol 489 (2) ◽  
pp. 1899-1918 ◽  
Author(s):  
S I Raimundo ◽  
A Pancoast ◽  
M Vestergaard ◽  
M R Goad ◽  
A J Barth
Keyword(s):  
Black Hole ◽  
High Redshift ◽  
Monitoring Data ◽  
Test Case ◽  
Broad Line ◽  
Broad Line Region ◽  
Line Region ◽  
Single Epoch ◽  
Black Hole Masses ◽  
Dynamical Modelling

ABSTRACT We show that individual (single-epoch) spectra of active galactic nuclei (AGNs) can constrain some of the geometry and dynamics of the AGN broad line region. Studies of the cosmic influence of supermassive black holes are limited by the current large uncertainties in the determination of black hole masses. One dominant limitation is the unknown geometry, dynamics, and line-of-sight inclination of the broad line region, used to probe the central black hole mass. Recent progress has been made to constrain the spatial and kinematic structure of the broad line region using dynamical modelling of AGN monitoring data and an underlying physical model for the broad line region. In this work we test the ability of a modified version of this dynamical modelling code to constrain the broad line region structure using single-epoch spectra. We test our modelling code on single-epoch spectra of nearby Arp 151 by comparing our results with those obtained with monitoring data of this same object. We find that a significant fraction of the broad line region parameters can indeed be adequately constrained, with uncertainties that are comparable to, or at most a factor of approximately a few higher than those obtained from modelling of monitoring data. Considering the wealth of available single-epoch spectroscopic observations, this method is promising for establishing the overall AGN population trends in the geometry and dynamics of the broad line region. This method can be applied to spectra of AGNs at low and high redshift making it valuable for studies of cosmological black hole and AGN evolution.

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