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A Radio Galaxy at z=5.19

Wil van Breugel·Carlos De Breuck·S. A. Stanford·Dan Stern·Huub Rottgering·George Miley
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Abstract

We report the discovery of the most distant known AGN, the radio galaxy TN J0924-2201 at z = 5.19. The radio source was selected from a new sample of ultra-steep spectrum (USS) sources, has an extreme radio spectral index alpha_365MHz^1.4GHz = -1.63, and is identified at near-IR wavelengths with a very faint, K = 21.3 +- 0.3 object. Spectroscopic observations show a single emission line at lambda ~ 7530A, which we identify as Ly-alpha. The K-band image, sampling rest frame U-band, shows a multi-component, radio-aligned morphology, typical of lower-redshift radio galaxies. TN J0924-2201 extends the near-IR Hubble, or K-z, relation for powerful radio galaxies to z > 5, and is consistent with models of massive galaxies forming at even higher redshifts.

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Wil van Breugel, Carlos De Breuck, S. A. Stanford, Dan Stern, Huub Rottgering, George Miley. 1999-04-21. A Radio Galaxy at z=5.19. https://doi.org/10.1086/312080

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