The application of the Mid-IR radio correlation to the $\hat{G}$ sample
  and the search for advanced extraterrestrial civilisations
  Wright et al. 2014 have embarked on a search for advanced Karadashev Type III
civilisations via the compilation of a sample of sources with extreme mid-IR
emission and colours. In this scenario, the mid-IR emission is then primarily
associated with waste heat energy by-products. I apply the Mid-IR radio
correlation to this $\hat{G}$ sample (Griffith et al. 2015). I demonstrate that
the mid-IR and radio luminosities are correlated for the sample with
$q_{22}=1.35\pm0.42 $. By comparison, the First Look Survey (FLS) has
$q_{22}=0.87\pm0.27$. The fact that the G-HAT sample largely follows the Mid-IR
radio correlation, strongly suggests the vast majority of these sources are
associated with galaxies in which natural astrophysical processes are dominant.
This simple application of the mid-IR radio correlation can substantially
reduce the number of false positives in the $\hat{G}$ catalogue, since galaxies
occupied by advanced Kardashev Type III civilisations would be expected to
exhibit very high values of $q$. Indeed I identify 9 outliers in the sample
with $q_{22} > 2$ of which at least 3 have properties that are relatively well
explained via standard astrophysical interpretations e.g. dust emission
associated with nascent star formation and/or nuclear activity from a heavily
obscured AGN. I also note that the comparison of resolved Mid-IR and radio
images of galaxies on sub-galactic (kpc) scales can also be useful in
identifying and recognising artificial mid-IR emission from less advanced
intermediate Type II/III civilisations. Nevertheless, from the bulk properties
of the $\hat{G}$ sample, I conclude that Kardashev Type-III civilisations are
either very rare or do not exist in the local Universe.
