The discovery of a typical radio galaxy at z = 4.88
  In this letter we report the discovery of a z=4.88 radio galaxy discovered
with a new technique which does not rely on pre-selection of a sample based on
radio properties such as steep-spectral index or small angular size. This radio
galaxy was discovered in the Elais-N2 field and has a spectral index of alpha =
0.75, i.e. not ultra-steep spectrum. It also has a luminosity consistent with
being drawn from the break of the radio luminosity function and can therefore
be considered as a typical radio galaxy. Using the Spitzer-SWIRE data over this
field we find that the host galaxy is consistent with being similarly massive
to the lower redshift powerful radio galaxies (~1-3L*). We note however, that
at z=4.88 the H-alpha line is redshifted into the IRAC 3.6micron filter and
some of the flux in this band may be due to this rather than stellar continuum
emission. The discovery of such a distant radio source from our initial
spectroscopic observations demonstrate the promise of our survey for finding
the most distant radio sources.
