Book contents
- Frontmatter
- Contents
- Index of Participants
- Preface
- I Evidence and Implications of Anisotropy in AGN
- II Luminosity Functions and Continuum Energy Distributions
- III The Broad Line Region: Variability and Structure
- Emission Line and Continuum Variability in Active Galactic Nuclei
- Results of the LAG Monitoring Campaign
- A Relation Between the Profiles and Intensities of Broad Emission Lines
- Broad Line Profile Variability in NGC 4593
- Deconvolution of Variable Seyfert 1 Profiles
- Ultra-violet Variability of AGN
- Broad-Line Variations in NGC 5548
- NGC 4593: A Low Luminosity Compact Seyfert 1 Nucleus
- UV Continuum Origin and BLR Structure in F-9
- UV Emission Line Intensities and Variability: a Self Consistent Model for Broad-Line Emitting Gas in NGC 3783
- Non-Linear Anisotropic BLR Models
- Anisotropic Line Emission from Extended BLR's
- Active Galactic Nuclei and Nuclear Starbursts
- Rapidly Evolving Compact SNRs and the Nature of the Lag in AGNs
- Supernova Explosions in QSOs? - II
- High Metallicities in QSOs
- The Chemical Evolution of QSOs
- Non-Linearity of Ly α Response in Variable AGNs
- Implications of Broad Line Profile Diversity among AGN
- Emission Line Studies of AGN
- A Search for Velocity Shifts in QSO Broad Lines
- Broad Line Region Structure from Profile Shapes
- IV X-rays and Accretion Disks
- V Beams, Jets and Blazars
- VI Concluding Talk
Results of the LAG Monitoring Campaign
from III - The Broad Line Region: Variability and Structure
Published online by Cambridge University Press: 04 August 2010
- Frontmatter
- Contents
- Index of Participants
- Preface
- I Evidence and Implications of Anisotropy in AGN
- II Luminosity Functions and Continuum Energy Distributions
- III The Broad Line Region: Variability and Structure
- Emission Line and Continuum Variability in Active Galactic Nuclei
- Results of the LAG Monitoring Campaign
- A Relation Between the Profiles and Intensities of Broad Emission Lines
- Broad Line Profile Variability in NGC 4593
- Deconvolution of Variable Seyfert 1 Profiles
- Ultra-violet Variability of AGN
- Broad-Line Variations in NGC 5548
- NGC 4593: A Low Luminosity Compact Seyfert 1 Nucleus
- UV Continuum Origin and BLR Structure in F-9
- UV Emission Line Intensities and Variability: a Self Consistent Model for Broad-Line Emitting Gas in NGC 3783
- Non-Linear Anisotropic BLR Models
- Anisotropic Line Emission from Extended BLR's
- Active Galactic Nuclei and Nuclear Starbursts
- Rapidly Evolving Compact SNRs and the Nature of the Lag in AGNs
- Supernova Explosions in QSOs? - II
- High Metallicities in QSOs
- The Chemical Evolution of QSOs
- Non-Linearity of Ly α Response in Variable AGNs
- Implications of Broad Line Profile Diversity among AGN
- Emission Line Studies of AGN
- A Search for Velocity Shifts in QSO Broad Lines
- Broad Line Region Structure from Profile Shapes
- IV X-rays and Accretion Disks
- V Beams, Jets and Blazars
- VI Concluding Talk
Summary
Abstract
We present evidence for changes in the transfer function of the broad line region (BLR) in NGC 3516 on time scales of a couple of months. If this occurs in most AGN, it would mean a serious complicating factor for mapping the BLR by reverberation methods. Furthermore, the Hβ profile in this object shows a time-variable dip at the same velocity shift as the strong absorption in CIV λ1550. A corresponding feature is not present in Hα. The question addressed is whether the Hβ dip is absorption or a dip between two emission peaks. These results are part of the LAG project: during the first five months in 1990, a sample of 6 Seyfert-1 galaxies and 2 QSO's were monitored spectroscopically and photometrically. Significant line-profile changes were found in the lower luminosity objects in the sample. The higher luminosity objects displayed continuum variations only.
The time variable transfer function in NGC 3516
In this section we will show that the transfer function of the BLR in NGC 3516 changed significantly over a time scale of several months. This observation could have a profound impact on the use of reverberation mapping as a means to map the structure of the BLR, because it is one of the basic assumptions of reverberation mapping that the transfer function does not change during the experiment.
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- The Nature of Compact Objects in Active Galactic NucleiProceedings of the 33rd Herstmonceux Conference, held in Cambridge, July 6-22, 1992, pp. 167 - 175Publisher: Cambridge University PressPrint publication year: 1994