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
UV Emission Line Intensities and Variability: a Self Consistent Model for Broad-Line Emitting Gas in NGC 3783
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
Short-wavelength IUE archival data for NGC 3783 were re-extracted and analysed to constrain numerical modelling parameters in detailed photoionization analyses. The He IIλ1640, C IVλ1549, and C IIIλ1909 line intensities and trends can be reasonably well reproduced by a two cloud component model. In order to produce satisfactory line intensities or trends for other higher ionization lines and lower ionization lines, still more gas components are necessary with gas density ranging from roughly 1011 cm−3 to 109 cm−3 or less. In going from the inner to outer clouds, the optical depth increases and the gas density decreases approximately as r−2.
The amount of dust obscuration along the line of sight, as required by the models, is consistent with reddening estimates from HeII line ratios, and CNO abundance ratios derived from intercombination line intensities suggest abundances of carbon, nitrogen and oxygen lower by a factor of about 2 relative to solar. The HeII line rest equivalent widths from the models suggest a gas covering factor of order 0.25.
Introduction
Although sophisticated numerical photoionization models have been employed for two decades in investigations of the broad–line–emitting regions (BLRs) of Seyfert 1 galaxies, some of the most fundamental BLR properties such as the intrinsic ionizing radiation field, the ionization parameter, emitting gas density, chemical abundances, and the “covering factor” (the fraction of solid angle occupied by optically thick gas around the ionizing radiation source) are still open to question.
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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. 199 - 202Publisher: Cambridge University PressPrint publication year: 1994