SuperCLASS -- II: Photometric Redshifts and Characteristics of
  Spatially-Resolved $\mu$Jy Radio Sources
  We present optical and near-infrared imaging covering a $\sim$1.53 deg$^2$
region in the Super-Cluster Assisted Shear Survey (SuperCLASS) field, which
aims to make the first robust weak lensing measurement at radio wavelengths. We
derive photometric redshifts for $\approx$176,000 sources down to
$i^\prime_{\rm AB}\sim24$ and present photometric redshifts for 1.4 GHz
$e$-MERLIN and VLA detected radio sources found in the central 0.26 deg$^{2}$.
We compile an initial catalog of 149 radio sources brighter than S$_{1.4}>75$
$\mu$Jy and find their photometric redshifts span $0<z_{\rm phot}<4$ with radio
luminosities between $10^{21}-10^{25}$ W Hz$^{-1}$, with medians of $\langle z
\rangle =0.55$ and $\langle L_{1.4}\rangle =1.9\times10^{23}$ W Hz$^{-1}$
respectively. We find 95% of the \uJy\ radio source sample (141/149) have SEDs
best fit by star-forming templates while 5% (8/149) are better fit by AGN.
Spectral indices are calculated for sources with radio observations from VLA
and GMRT at 325 MHz, with an average spectral slope of $\alpha=0.59\pm0.04$.
Using the full photometric redshift catalog we construct a density map at the
redshift of the known galaxy clusters, $z=0.20\pm0.08$. Four of the five
clusters are prominently detected at $>7 \sigma$ in the density map and we
confirm the photometric redshifts are consistent with previously measured
spectra from a few galaxies at the cluster centers.
