3C-65 - OLD GALAXY OR BURIED QUASAR

M LACY, S RAWLINGS, S EALES, J S DUNLOP

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Abstract

3C 65 is one of the reddest known radio galaxies at z approximate to 1. We have taken optical and near-infrared spectra, and a K-band image in an attempt to assess whether this red colour is produced by an underlying old stellar population. We find that the broad- and intermediate-band fluxes are consistent with a power-law spectrum in the optical/near-infrared, with no evidence for a 4000-Angstrom break, showing that the K-band light is dominated by a reddened quasar nucleus. By comparing the optical spectral index with the mean for optically selected quasars, we estimate an A(V) approximate to 2 towards the nucleus and an unreddened quasar magnitude of V approximate to 19. Our spectra, however, do indicate the presence of a 4000-Angstrom break in the off-nuclear light, consistent with either a formation redshift z(f) > 4 for a stellar population with a standard IMF, or the presence of young supergiant stars, which we have previously argued are present in the off-nuclear knot of 3C 356.

Original languageEnglish
Pages (from-to)821-826
Number of pages6
JournalMonthly Notices of the Royal Astronomical Society
Volume273
Issue number3
Publication statusPublished - 1 Apr 1995

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