Near‐ and Mid‐Infrared Photometry of High‐Redshift 3CR Sources
View/ Open
Author
Haas, Martin
Heymann, Frank
Chini, Rolf
Siebenmorgen, Ralf
Published Version
https://doi.org/10.1086/592085Metadata
Show full item recordCitation
Haas, Martin, S. P. Willner, Frank Heymann, M. L. N. Ashby, G. G. Fazio, Belinda J. Wilkes, Rolf Chini, and Ralf Siebenmorgen. 2008. “Near‐ and Mid‐Infrared Photometry of High‐Redshift 3CR Sources.” The Astrophysical Journal 688 (1) (November 20): 122–127. doi:10.1086/592085.Abstract
Using the Spitzer Space Telescope, we have obtained 3.6-24 μm photometry of 38 radio galaxies and 24 quasars from the 3CR (Third Cambridge Revised Catalog of Radio Sources) at redshift 1 < z < 2.5. This 178 MHz selected sample is unbiased with respect to orientation and therefore suited to study orientation-dependent effects in the most powerful active galactic nuclei (AGNs). Quasar and radio galaxy subsamples matched in isotropic radio luminosity are compared. The quasars all have similar spectral energy distributions (SEDs), nearly constant in νFν through the rest 1.6-10 μm range, consistent with a centrally heated dust distribution that outshines the host galaxy contribution. The radio galaxy SEDs show larger dispersion, but the mean radio galaxy SED declines from rest 1.6 to 3 μm and then rises from 3 to 8 μm. The radio galaxies are on average a factor 3-10 less luminous in this spectral range than the quasars. These characteristics are consistent with composite emission from a heavily reddened AGN plus starlight from the host galaxy. The mid-infrared colors and radio to mid-infrared spectral slopes of individual galaxies are also consistent with this picture. Individual galaxies show different amounts of extinction and host galaxy starlight, consistent with the orientation-dependent unified scheme.Other Sources
https://arxiv.org/abs/0807.3966Terms of Use
This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAACitable link to this page
http://nrs.harvard.edu/urn-3:HUL.InstRepos:29921882
Collections
- FAS Scholarly Articles [18304]
Contact administrator regarding this item (to report mistakes or request changes)