Inskip, K.J., Best, P.N. and Longair, M.S. (2006) Deviations from passive evolution – star formation and the ultraviolet excess in z ∼ 1 radio galaxies. Monthly Notices of the Royal Astronomical Society, 367 (2). pp. 693-708. ISSN 0035-8711
Abstract
Galaxy colours are determined for two samples of 6C and 3CR radio sources at z∼ 1, differing by a factor of∼6 in radio power. Corrections are made for emission-line contamination and the presence of any nuclear point source, and the data analysed as a function of both redshift and the radio source properties. The galaxy colours are remarkably similar for the two populations, and the ultraviolet excess evolves with radio source size similarly in both samples, despite the fact that the alignment effect is more extensive for the more powerful 3CR radio galaxies. These results seem to suggest that the alignment effect at these redshifts does not scale strongly with radio power, and is instead more closely dependent on galaxy mass (which is statistically comparable for the two samples). However, it is likely that the presence of relatively young (≲several times 108-yr-old) stellar populations has considerably contaminated the K-band flux of these systems, particularly in the case of the more powerful 3CR sources, which are∼0.5 mag more luminous than the predictions of passive evolution models at z∼ 1. The higher luminosity of the 3CR alignment effect is balanced by emission at longer wavelengths, thereby leading to comparable colours for the two samples.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2006 The Authors. Reproduced in accordance with the publisher's self-archiving policy. |
Keywords: | galaxies : active; galaxies : evolution; galaxies : photometry |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 10 Apr 2019 15:44 |
Last Modified: | 10 Apr 2019 15:44 |
Status: | Published |
Publisher: | Oxford University Press |
Refereed: | Yes |
Identification Number: | 10.1111/j.1365-2966.2006.10005.x |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:144715 |