Book contents
- Frontmatter
- Contents
- Index of Participants
- Preface
- I Evidence and Implications of Anisotropy in AGN
- Evidence for Anisotropy and Unification
- Any Evidence against Unified Schemes?
- Spectropolarimetry of Cygnus A
- Spectropolarimetery of the Ultraluminous Infrared Galaxy IRAS 110548–1131
- Are there Dusty Tori in Seyfert 2 Galaxies?
- Imaging Spectrophotometry of Extended-Emission Seyfert Galaxies
- Spectroscopy of the Extended Emission Line Regions in NGC 4388
- Evidence and Implications of Anisotropy in Seyfert Galaxies
- Collimated Radiation in NGC 4151
- A Dust Ring around the Nucleus of NGC 4151
- Evolution of Narrow Line Clouds
- Star Formation in NGC 5953
- Stellar Activity in the Seyfert Nucleus of NGC 1808
- Direct Evidence for Anisotropy: Radio Maps and their Relation to Optical Morphology
- The Radio-Optical Connection in AGN
- Knots in Extragalactic Radio Jets
- Radio Emission and the Nature of Compact Objects in AGN
- The Radio Properties of Hidden Seyfert 1's: Implications for Unified Models
- Anisotropic Optical Continuum Emission in Radio Quasars
- The UV Component in Distant Radio Galaxies
- A Connection between BL Lacertæ Objects and Flat-Spectrum Radio Quasars?
- The Difference between BL Lacs and QSOs
- The Evolutionary Unified Scheme and the θ-z Plane
- II Luminosity Functions and Continuum Energy Distributions
- III The Broad Line Region: Variability and Structure
- IV X-rays and Accretion Disks
- V Beams, Jets and Blazars
- VI Concluding Talk
Imaging Spectrophotometry of Extended-Emission Seyfert Galaxies
from I - Evidence and Implications of Anisotropy in AGN
Published online by Cambridge University Press: 04 August 2010
- Frontmatter
- Contents
- Index of Participants
- Preface
- I Evidence and Implications of Anisotropy in AGN
- Evidence for Anisotropy and Unification
- Any Evidence against Unified Schemes?
- Spectropolarimetry of Cygnus A
- Spectropolarimetery of the Ultraluminous Infrared Galaxy IRAS 110548–1131
- Are there Dusty Tori in Seyfert 2 Galaxies?
- Imaging Spectrophotometry of Extended-Emission Seyfert Galaxies
- Spectroscopy of the Extended Emission Line Regions in NGC 4388
- Evidence and Implications of Anisotropy in Seyfert Galaxies
- Collimated Radiation in NGC 4151
- A Dust Ring around the Nucleus of NGC 4151
- Evolution of Narrow Line Clouds
- Star Formation in NGC 5953
- Stellar Activity in the Seyfert Nucleus of NGC 1808
- Direct Evidence for Anisotropy: Radio Maps and their Relation to Optical Morphology
- The Radio-Optical Connection in AGN
- Knots in Extragalactic Radio Jets
- Radio Emission and the Nature of Compact Objects in AGN
- The Radio Properties of Hidden Seyfert 1's: Implications for Unified Models
- Anisotropic Optical Continuum Emission in Radio Quasars
- The UV Component in Distant Radio Galaxies
- A Connection between BL Lacertæ Objects and Flat-Spectrum Radio Quasars?
- The Difference between BL Lacs and QSOs
- The Evolutionary Unified Scheme and the θ-z Plane
- II Luminosity Functions and Continuum Energy Distributions
- III The Broad Line Region: Variability and Structure
- IV X-rays and Accretion Disks
- V Beams, Jets and Blazars
- VI Concluding Talk
Summary
Abstract
We present highlights of a multi-band optical imaging study of the ENLRs in seven Seyfert galaxies. Flux-calibrated narrowband emission-line and continuum images obtained in subarcsecond seeing conditions with the 3.6m CFHT reveal a remarkable wealth of emission-line and optical continuum structures. We show an example from our data of an apparent mechanical interaction between radio plasma ejecta and the ENLR, and describe an extended near-UV continuum component, which appears to be scattered nuclear continuum light, that is seen in all of the five Seyfert 2s, but is conspicuously absent in the two extended-emission Seyfert 1s.
Introduction
Many Seyfert nuclei are surrounded by kpc-scale regions of highly ionized gas known as the “extended narrow-line region” (ENLR). The energetics, ionization state, and morphology of the ENLR have been one of our most powerful probes of the interaction between a Seyfert nucleus and its host galaxy environment. Traditionally, the ENLR in Seyferts has been mapped using CCD images taken through narrow interference filters isolating the bright emission lines of Hα+[N II] and [O III]λ5007. These lines bracket a wide range of ionization potential, and so provide a simple, qualitative diagnostic of the ionization state of the gas. Two-band imaging surveys have had a fair amount of success so far at revealing extended emission in Seyferts and other AGN [1,2]. Often, however, one wants more quantitative information such as a particular line ratio which is diagnostic of a nebular parameter.
- Type
- Chapter
- Information
- The Nature of Compact Objects in Active Galactic NucleiProceedings of the 33rd Herstmonceux Conference, held in Cambridge, July 6-22, 1992, pp. 36 - 39Publisher: Cambridge University PressPrint publication year: 1994