The size of broad-line regions of low-luminosity active galactic nuclei

  title={The size of broad-line regions of low-luminosity active galactic nuclei},
  author={Zhang Xue-guang and Deborah Dultzin-Hacyan and Wang Ting-gui},
  journal={Monthly Notices of the Royal Astronomical Society},
We study the size of broad-line regions (BLRs) of low-luminosity active galactic nuclei (AGN), also called 'dwarf AGN',defined as having L Hα ≤ 10 41 erg s- 1 . We more than double the sample size analysed previously by Wang & Zhang. In this study we first confirm our previous result -that the sizes of BLRs of low-luminosity AGN are larger than those expected from the empirical relation R BLRs -L Hα valid for 'normal' AGN (Seyfert Is and quasars), except for objects with accretion rate m H… 

Figures and Tables from this paper

The sizes of broad emission line regions and black hole masses of double‐peaked broad low‐ionization emission line objects
In this paper, the sizes of the broad emission line regions (BLRs) and black hole (BH) masses of double-peaked broad low-ionization emission line emitters (DBP emitters) are compared using different
The HST view of the broad line region in low luminosity AGN
We analyze the properties of the broad line region (BLR) in low luminosity AGN by using HST/STIS spectra. We consider a sample of 24 nearby galaxies in which the presence of a BLR has been reported
Giant Broad Line Regions in Dwarf Seyferts
High angular resolution spectroscopy obtained with the Hubble Space Telescope (HST) has revealed a remarkable population of galaxies hosting dwarf Seyfert nuclei with an unusually large broad-line
Partly obscured accretion disc model to explain shifted broad Balmer emission lines of active galactic nuclei
We present a new model to explain the appearance of red/blueshifted broad low-ionization emission lines, especially emission lines in the optical band, which is commonly considered as an indicator of
The correlation between spectral index and accretion rate for AGN
In this paper, we present a correlation between the spectral index distribution (SED) and the dimensionless accretion rate defined as m = L bol /L Edd for active galactic nuclei (AGN). This quantity
AGN population in Hickson's Compact Groups. I. Data and Nuclear Activity Classification
We have conducted a new spectroscopic survey to characterize the nature of nuclear activity in Hickson compact group (HCG) galaxies and establish its frequency. We have obtained new
Nuclear Activity in Nearby Galaxies
A significant fraction of nearby galaxies show evidence of weak nuclear activity unrelated to normal stellar processes. Recent high-resolution, multiwavelength observations indicate that the bulk of
Photoionization modelling of the giant broad-line region in NGC 3998
Prior high angular resolution spectroscopic observations of the Low-ionization nuclear emission-line region (Liner) in NGC 3998 obtained with the Space Telescope Imaging Spectrograph (STIS) aboard
‘Disc–Jet’ Coupling in Black Hole X-Ray Binaries and Active Galactic Nuclei
In this chapter I will review the status of our phenomenological understanding of the relation between accretion and outflows in accreting black hole systems. This understanding arises primarily from
Subaru and e-Merlin observations of NGC 3718. Diaries of a supermassive black hole recoil?
NGC3718 is a LINER $L1.9$ galaxy, lying at a distance of about $\sim 17.4$ Mpc away from earth and its similarities with NGC5128 often award it the name "northern Centaurus A". We use high angular


The size of the broad‐line regions in dwarf active galaxies
Using the empirical relation between black hole mass and bulge velocity dispersion established for active and quiescent galaxies, we derive the sizes of the broad-line regions (BLRs) for 22 dwarf
The Relationship between Luminosity and Broad-Line Region Size in Active Galactic Nuclei
We reinvestigate the relationship between the characteristic broad-line region size (RBLR) and the Balmer emission-line, X-ray, UV, and optical continuum luminosities. Our study makes use of the best
Active Galactic Nuclei with Candidate Intermediate-Mass Black Holes
We present an initial sample of 19 intermediate-mass black hole candidates in active galactic nuclei culled from the first data release of the Sloan Digital Sky Survey. Using the line
Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. I. Comparing the Photoionization and Reverberation Techniques
The masses and emission-line region sizes of active galactic nuclei (AGNs) can be measured by "reverberation-mapping" techniques, and we use these results to calibrate similar determinations made by
A Search for “Dwarf” Seyfert Nuclei. IV. Nuclei with Broad Hα Emission
We present the results of an optical spectroscopic survey designed to search for low-luminosity “dwarf” Seyfert nuclei in a magnitude-limited (BT ≤ 12.5 mag) sample of 486 bright, northern galaxies.
Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
Correlated variations in the line and continuum emission from active galactic nuclei (AGNs) can be used to determine the size and geometry of the broad emission-line regions (BLRs). We have
Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database
We present improved black hole masses for 35 active galactic nuclei (AGNs) based on a complete and consistent reanalysis of broad emission-line reverberation-mapping data. From objects with multiple
Physical Conditions in the Emission-Line Gas in the Extremely Low Luminosity Seyfert Nucleus of NGC 4395
We have combined Hubble Space Telescope/Faint Object Spectrograph, ground-based, and Infrared Space Observatory spectra of the nucleus of NGC 4395, the least luminous and nearest known type 1 Seyfert
The Broad-Line and Narrow-Line Regions of the LINER NGC 4579
We report the discovery of an extremely broad Hα emission line in the LINER nucleus of NGC 4579. From ground-based observations, the galaxy was previously known to contain a type 1 nucleus with a
Black hole mass estimation using a relation between the BLR size and emission line luminosity of AGN
An empirical relation between the broad line region (BLR) size and optical continuum luminosity is often adopted to estimate the BLR size and then the black hole mass of AGNs. However, optical