An Investigation into the Effects of Luminosity on the Mid-Infrared Spectral Energy Distributions of Radio-Quiet Quasars

Abstract

We present an analysis of the effects of luminosity on the shape of the mid-infrared spectral energy distributions (SEDs) of 234 radio-quiet quasars originally presented by Richards et al. In quasars without evident dust extinction, the spectrally integrated optical and infrared luminosities are linearly correlated over nearly three decades in luminosity. We find a significant (>99.99% confidence) correlation between the 1.8-8.0 micron spectral index and infrared luminosity that indicates an enhancement of the mid-infrared continuum with increasing luminosity. Coupled with strong evidence for spectral curvature in more luminous quasars, we conclude this trend is likely a manifestation of the `near-infrared (3-5 micron) bump' noticed in earlier quasar SED surveys. The strength of this feature is indicative of the contribution of emission from the hottest (>1000 K) dust to the mid-infrared spectrum; higher luminosity quasars tend to show more hot dust emission. Finally, the comparable distribution of bolometric corrections from the monochromatic 3 micron luminosity as well as its lack of sensitivity to dust extinction as compared to the standard bolometric correction from nu*L_{5100A} suggest that the former may be a more robust indicator of bolometric quasar luminosity. The close link between the power in the mid-infrared and optical and the effect of luminosity on the shape of the mid-infrared continuum indicate that considering mid-infrared emission independent of the properties of the quasar itself is inadequate for understanding the parsec-scale quasar environment.

arXiv commentComments: 13 pages, 11 figures (3 color), uses emulateapj. Accepted for publication in ApJ

References in corpus (31)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• The Sloan Digital Sky Survey: Technical Summary
• Composite Quasar Spectra From the Sloan Digital Sky Survey
• Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars
• Cosmological Evolution of the Hard X-ray AGN Luminosity Function and the Origin of the Hard X-ray Background
• The SDSS Quasar Survey: Quasar Luminosity Function from Data Release Three
• Revisiting the Infrared Spectra of Active Galactic Nuclei with a New Torus Emission Model
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• The AGN Obscuring Torus -- End of the "Doughnut" Paradigm?
• Dust Emission from Active Galactic Nuclei
• Self-similarity and scaling behavior of IR emission from radiatively heated dust: I. Theory
• Red and Reddened Quasars in the Sloan Digital Sky Survey
• Broad Emission Line Shifts in Quasars: An Orientation Measure for Radio-Quiet Quasars?
• The Sloan Digital Sky Survey Quasar Catalog III. Third Data Release
• Dust Reddening in SDSS Quasars
• Soft X-ray and Ultraviolet Emission Relations in Optically Selected AGN Samples
• Spitzer Quasar and ULIRG evolution study (QUEST): I. The origin of the far infrared continuum of QSOs
• Active Galactic Nuclei in the Sloan Digital Sky Survey: II. Emission-Line Luminosity Function
• The Detection of Silicate Emission from Quasars at 10 and 18 Microns
• Towards a physical model of dust tori in Active Galactic Nuclei - Radiative transfer calculations for a hydrostatic torus model
• Probing the Evolution of IR Properties of z~6 Quasars: Spitzer Observations
• Clumpy tori around active galactic nuclei
• Chandra Observations of the Highest Redshift Quasars from the Sloan Digital Sky Survey
• XMM and Chandra measurements of the AGN intrinsic absorption: dependence on luminosity and redshift
• The 1<z<5 Infrared Luminosity Function of Type I Quasars
• The Baldwin Effect and Black Hole Accretion: A Spectral Principal Component Analysis of a Complete QSO Sample
• The near-infrared spectrum of Mrk 1239: direct evidence of the dusty torus?
• New radiative transfer models for obscuring tori in active galaxies
• Dust Emission from Quasars and Quasar Host Galaxies
• Observational Evidence for a Multiphase Outflow in QSO FIRST J1044+3656
• Spitzer Observations of High Redshift QSOs

Cited by in corpus (34)

• The Stellar Mass Content of Submillimeter-Selected Galaxies
• Hot Graphite Dust and the Infrared Spectral Energy Distribution of Active Galactic Nuclei
• Mean Spectral Energy Distributions and Bolometric Corrections for Luminous Quasars
• The Obscured Fraction of AGN in the XMM-COSMOS Survey: A Spectral Energy Distribution Perspective
• The Spitzer High Redshift Radio Galaxy Survey
• Type 1 AGN at low z. II. The relative strength of narrow lines and the nature of intermediate type AGN
• A Kiloparsec-Scale Binary Active Galactic Nucleus Confirmed by the Expanded Very Large Array
• Properties of dusty tori in AGN: I. The Case of SWIRE/SDSS Quasars
• The Spitzer mid-infrared AGN survey. II-the demographics and cosmic evolution of the AGN population
• Radio Through X-ray Spectral Energy Distributions of 38 Broad Absorption Line Quasars
• Hot Dust Clouds with Pure Graphite Composition around Type-I Active Galactic Nuclei
• The Mid-Infrared Continua of Seyfert Galaxies
• Complete infrared spectral energy distributions of mm detected quasars at z>5
• The near-to-mid infrared spectrum of quasars
• Mid-Infrared Spectroscopic Properties of Ultra-Luminous Infrared Quasars
• Dusty Tori of Luminous Type 1 Quasars at z \sim 2
• Determining the torus covering factors for a sample of type 1 AGN in the local Universe
• Mid-infrared spectroscopy of high-redshift 3CRR sources
• The Physical Properties of Low Redshift FeLoBAL Quasars. I. Spectral Synthesis Analysis of the BAL Outflows using $SimBAL$
• An Infrared Comparison of Type-1 and Type-2 Quasars
• A Luminous Transient Event in a Sample of WISE-Selected Variable AGN
• Evidence for Radiation Pressure Compression in the X-ray Narrow Line Region of Seyfert galaxies
• SDSS J075101.42+291419.1: A Super-Eddington Accreting Quasar with Extreme X-ray Variability
• The WISSH quasars project XI. The mean Spectral Energy Distribution and Bolometric Corrections of the most luminous quasars
• The UV--mid-IR Spectral Energy Distribution of a z=1.7 Quasar Host Galaxy
• The Binary Black Hole Model for Mrk 231 Bites the Dust
• The Properties of Low-Redshift FeLoBAL Quasars: III. The Location and Geometry of the Outflows
• The Physical Properties of Low-Redshift FeLoBAL Quasars: II. The Rest-Frame Optical Emission Line Properties
• How does the radio enhancement of broad absorption line quasars relate to colour and accretion rate?
• The Mid-Infrared Luminosity Evolution and Luminosity Function of Quasars with SDSS and WISE
• Characterizing Quasars in the Mid-infrared: High Signal-to-Noise Spectral Templates
• HYPERION: broad-band X-ray-to-near-infrared emission of Quasars in the first billion years of the Universe
• What is the origin of the stacked radio emission in radio-undetected quasars?: Insights from a radio-infrared image stacking analysis
• Looking for the Wind in the Dust