Physical Properties of Luminous Dust Poor Quasars

Abstract

We identify and characterize a population of luminous dust poor quasars at 0<z<5, similar in photometric properties to the objects found at z>6 previously. This class of active galactic nuclei has been known to show little IR emission from a dusty structure, but is yet poorly understood in terms of number evolution or of dependence on physical quantities. In order to better understand the luminous dust poor quasar properties, we compiled a rest-frame UV to IR library of 41,000 optically selected type-1 quasars with $L_{bol}>10^{45.7}erg{s}^{-1}$. After fitting the broad-band spectral energy distributions (SEDs) with accretion disk and dust components, we find 0.6% of our sample to be hot dust poor with a rest-frame 2.3 micron to 0.51 micron flux density ratio of -0.5 dex or less. The dust poor SEDs are blue in the UV-optical and weak in the MIR, such that their accretion disks are less obscured, and that hot dust emission traces that of warm dust down to the dust poor regime. At a given bolometric luminosity, dust poor quasars are lower in black hole mass and higher in Eddington ratio than general luminous quasars, suggesting that they are in a rapidly growing evolutionary state in which the dust poor phase appears as a short or rare phenomenon. The dust poor fraction increases with redshift, and possible implications for the evolution of the dust poor fraction are discussed.

17 pages, accepted to ApJ, 1 machine-readable table to appear online

References in corpus (19)

• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• A Catalog of Quasar Properties from SDSS DR7
• A Catalog of Broad Absorption Line Quasars in Sloan Digital Sky Survey Data Release 5
• Major Galaxy Mergers Only Trigger the Most Luminous AGN
• The Sloan Digital Sky Survey quasar catalog: ninth data release
• Evidence for Quasar Activity Triggered by Galaxy Mergers in HST Observations of Dust-reddened Quasars
• Fe II Emission in 14 Low-Redshift Quasars: I - Observations
• The characteristic blue spectra of accretion disks in quasars as uncovered in the infrared
• A Strong Correlation between Circumnuclear Dust and Black Hole Accretion in Early-Type Galaxies
• Dust-free quasars in the early Universe
• The UV Continuum of Quasars: Models and SDSS Spectral Slopes
• The Baryonic Halos of Elliptical Galaxies: Radial Distribution of Globular Clusters and Diffuse Hot Gas
• Spitzer Observations of Young Red Quasars
• The Origin of Dust in Early-Type Galaxies and Implications for Accretion onto Supermassive Black Holes
• Evolutive Unification in Composite Active Galactic Nuclei
• NGC 5548: The AGN Energy Budget Problem and the Geometry of the Broad-Line Region and Torus
• The Mid-Infrared Fundamental Plane of Early-Type Galaxies
• A Quasar-Galaxy Mixing Diagram: Quasar Spectral Energy Distribution Shapes in the Optical to Near-Infrared

Cited by in corpus (22)

• Active Galactic Nuclei: what's in a name?
• Dust inflated accretion disc as the origin of the Broad Line Region in Active Galactic Nuclei
• Spectral Energy Distributions of QSOs at z>5: common AGN-heated dust and occasionally strong star-formation
• Do the Most Massive Black Holes at $z=2$ Grow via Major Mergers?
• Dust-Deficient Palomar-Green Quasars and the Diversity of AGN Intrinsic IR Emission
• Rest-frame Optical Spectra and Black Hole Masses of 3<z<6 Quasars
• The NuSTAR Serendipitous Survey: The 40 month Catalog and the Properties of the Distant High Energy X-ray Source Population
• Eddington-Limited Accretion in z~2 WISE-selected Hot, Dust-Obscured Galaxies
• No signs of star formation being regulated in the most luminous quasars at z~2 with ALMA
• Discovery of A Faint Quasar at z~6 and Implications for Cosmic Reionization
• The AKARI 2.5-5.0 Micron Spectral Atlas of Type-1 Active Galactic Nuclei: Black Hole Mass Estimator, Line Ratio, and Hot Dust Temperature
• Limits to Rest-Frame Ultraviolet Emission From Far-Infrared-Luminous z~6 Quasar Hosts
• Spectral Classification and Ionized Gas Outflows in $z\sim 2$ WISE-Selected Hot Dust-Obscured Galaxies
• Exploring the link between C IV outflow kinematics and sublimation-temperature dust in quasars
• The Dust-to-Gas Ratio and the Role of Radiation Pressure in Luminous, Obscured Quasars
• Mid-infrared Variability of Low-redshift Active Galactic Nuclei : Constraints on a Hot Dust Component with a Variable Covering Factor
• The Infrared Medium-deep Survey. IV. Low Eddington Ratio of A Faint Quasar at $z\sim 6$: Not Every Supermassive Black Hole is Growing Fast in the Early Universe
• The Most Massive Active Galactic Nuclei at $1\lesssim z\lesssim 2$
• A Fresh Look at AGN Spectral Energy Distribution Fitting with the XMM-SERVS AGN Sample
• High Star Formation Rates of Low Eddington Ratio Quasars at $z\gtrsim 6$
• HYPERION: broad-band X-ray-to-near-infrared emission of Quasars in the first billion years of the Universe
• Multi-band optical variability of a newly discovered twelve blazars sample from 2013-2019