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Extremely red radio galaxies

Chris J. Willott·Steve Rawlings·Katherine M. Blundell
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Abstract

At least half the radio galaxies at z>1 in the 7C Redshift Survey have extremely red colours (R-K>5), consistent with stellar populations which formed at high redshift (z>5). We discuss the implications of this for the evolution of massive galaxies in general and for the fraction of near-IR-selected EROs which host AGN, a result which is now being tested by deep, hard X-ray surveys. The conclusion is that many massive galaxies undergo at least two active phases: one at z~5 when the black hole and stellar bulge formed and another at z~1-2 when activity is triggered by an event such as an interaction or merger.

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Chris J. Willott, Steve Rawlings, Katherine M. Blundell. 2001-04-06. Extremely red radio galaxies. https://arxiv.org/abs/astro-ph/0104118

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