Radio--Far infrared correlation in "blue cloud" galaxies with 0<z<1.2
  We study the radio--far infrared (FIR) correlation in "blue cloud" galaxies
chosen from the PRism MUltiobject Survey (PRIMUS) up to redshift ($z$) of 1.2
in the XMM-LSS field. We use rest-frame emission at 1.4 GHz in the radio and
both monochromatic (at 70$\mu$m) and bolometric (between $8-1000~\mu$m)
emission in the FIR. To probe the nature of the correlation up to $z\sim1.2$,
where direct detection of blue star-forming galaxies is impossible with current
technology, we employ the technique of image stacking at 0.325 and 1.4 GHz in
the radio and in six infrared bands, viz. 24, 70, 160, 250, 350 and $500~\mu$m.
For comparison, we also study the correlation for more luminous galaxies that
are directly detected. The stacking analysis allows us to probe the radio--FIR
correlation for galaxies that are up to 2 orders of magnitude fainter than the
ones detected directly. The $k-$correction in the infrared wavebands is
obtained by fitting the observed spectral energy distribution (SED) with a
composite mid-IR power law and a single temperature greybody model. We find
that the radio luminosity at 1.4 GHz ($L_{\rm 1.4GHz}$) is strongly correlated
with monochromatic FIR luminosity at 70 $\mu$m ($L_{\rm 70\mu m}$) having slope
$1.09\pm0.05$ and with bolometric luminosity ($L_{\rm TIR}$) having slope
$1.11\pm0.04$. The quantity $q_{\rm TIR} (=\log_{10}[L_{\rm TIR}/(3.75\times
10^{12} L_{\rm 1.4 GHz})])$ is observed to decrease with redshift as $q_{\rm
TIR} \propto (1+z)^{-0.16\pm0.03}$ probably caused due to the non-linear slope
of the radio--FIR correlation. Within the uncertainties of our measurement and
the limitations of our flux-limited and color-selected sample, we do not find
any evolution of the radio--FIR correlation with redshift.
