Book contents
- Frontmatter
- Contents
- Index of Participants
- Preface
- I Evidence and Implications of Anisotropy in AGN
- II Luminosity Functions and Continuum Energy Distributions
- Radio Luminosity Functions of Active Galaxies
- The Quasar Luminosity Function
- UK ROSAT Deep & Extended Deep Surveys
- Luminosity Dependence of Optical Activity in Radio Galaxies
- Modelling the Quasar Luminosity Function in Hierarchical Models for Structure Formation
- Active Galactic Nuclei in Clusters of Galaxies
- Clustering Properties of AGNs and their Contribution to the X-ray Background
- Energy Distributions of AGN
- Absorption in the ROSAT X-ray Spectra of Quasars
- Dust in AGNs
- First Simultaneous UBVRI Photopolarimetric Observations of a Sample of Normal Quasars
- Intermediate Resolution Spectropolarimetry of Three Quasars
- Active Galaxies which Emit Strongly at 25μm
- III The Broad Line Region: Variability and Structure
- IV X-rays and Accretion Disks
- V Beams, Jets and Blazars
- VI Concluding Talk
The Quasar Luminosity Function
from II - Luminosity Functions and Continuum Energy Distributions
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
- Radio Luminosity Functions of Active Galaxies
- The Quasar Luminosity Function
- UK ROSAT Deep & Extended Deep Surveys
- Luminosity Dependence of Optical Activity in Radio Galaxies
- Modelling the Quasar Luminosity Function in Hierarchical Models for Structure Formation
- Active Galactic Nuclei in Clusters of Galaxies
- Clustering Properties of AGNs and their Contribution to the X-ray Background
- Energy Distributions of AGN
- Absorption in the ROSAT X-ray Spectra of Quasars
- Dust in AGNs
- First Simultaneous UBVRI Photopolarimetric Observations of a Sample of Normal Quasars
- Intermediate Resolution Spectropolarimetry of Three Quasars
- Active Galaxies which Emit Strongly at 25μm
- III The Broad Line Region: Variability and Structure
- IV X-rays and Accretion Disks
- V Beams, Jets and Blazars
- VI Concluding Talk
Summary
Abstract
Recent work on the quasar luminosity function at optical and X-ray wavelengths is reviewed. It is shown that the evolution of the quasar luminosity function in these regimes is marked by a strong and approximately similar power law increase in luminosity, L ∝ (1 + z)3±0.5, between the present epoch and z ∼ 2. At z > 2, a slow-down in the rate of quasar evolution is witnessed in both regimes with possible evidence for a decrease in the space density of quasars being seen amongst optically faint (MB > −27) QSOs at z > 3.5.
Introduction
The quasar luminosity function (LF) is one of the most fundamental statistics relating to the quasar population. Estimates of the quasar LF and its evolution with redshift are normally obtained from the statistical analysis of large unbiased quasar surveys with complete spectroscopic identification. As such, the rapid increase in the number of such surveys in recent years, particularly in the optical and X-ray regimes, has led to a dramatic improvement in our knowledge of the quasar LF and its evolution. The purpose of this review is to describe the current observational status of the quasar LF in the optical (4400Å) and X-ray (∼ 2keV ≡ 6.2Å) regimes.
The Optical Luminosity Function
As a result of the recent improvement in quasar statistics at B > 20, it has become increasingly clear (Koo 1983, Marshall 1987, Boyle et al. 1988, Koo & Kron 1988) that the low redshift (z < 3) quasar optical LF (OLF) exhibits a significant break in its power law slope at faint absolute magnitudes.
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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. 110 - 117Publisher: Cambridge University PressPrint publication year: 1994