The orientation dependence of quasar spectral energy distributions

Abstract

We investigate the orientation dependence of the spectral energy distributions in a sample of radio-loud quasars. Selected specifically to study orientation issues, the sample contains 52 sources with redshifts in the range 0.16<z<1.4 and measurements of radio core dominance, a radio orientation indicator. Measured properties include monochromatic luminosities at a range of wavelengths between the infrared and X-rays, integrated infrared luminosity, spectral slopes, and the covering fraction of the obscuring circumnuclear dust. We estimate dust covering fraction assuming that the accretion disk emits anisotropically and discuss the shortcomings and technical difficulties of this calculation. Luminosities are found to depend on orientation, with face-on sources factors of a 2-3 brighter than more edge-on sources, depending on wavelength. The degree of anisotropy varies very little with wavelength such that the overall shape of the spectral energy distribution does not vary significantly with orientation. In the infrared, we do not observe a decrease in anisotropy with increasing wavelength. The spectral slopes and estimates of covering fraction are not significantly orientation dependent. We construct composite spectral energy distributions as a function of radio core dominance and find that these illustrate the results determined from the measured properties.

13 pages, 6 figures, accepted to MNRAS

References in corpus (9)

• AGN Dusty Tori: I. Handling of Clumpy Media
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• Spitzer Quasar and ULIRG Evolution Study (QUEST): II. The Spectral Energy Distributions of Palomar-Green Quasars
• Dust covering factor, silicate emission and star formation in luminous QSOs
• Spitzer IRS spectra of a large sample of Seyfert galaxies: a variety of infrared SEDs in the local AGN population
• The mid IR -- hard X-ray correlation in AGN and its implications for dusty torus models
• Near- and mid-infrared photometry of high-redshift 3CR sources
• Unification scheme of radio galaxies and quasars falsified by their observed size distributions
• Does Size Matter? The Underlying Intrinsic Size Distribution of Radio Sources and Implications for Unification by Orientation

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