Wide-angle tail galaxies in ATLAS
  We present radio images of a sample of six Wide-Angle Tail (WAT) radio
sources identified in the ATLAS 1.4 GHz radio survey, and new spectroscopic
redshifts for four of these sources. These WATs are in the redshift range of
0.1469 - 0.3762, and we find evidence of galaxy overdensities in the vicinity
of four of the WATs from either spectroscopic or photometric redshifts. We also
present follow-up spectroscopic observations of the area surrounding the
largest WAT, S1189, which is at a redshift of ~0.22. The spectroscopic
observations, taken using the AAOmega spectrograph on the AAT, show an
overdensity of galaxies at this redshift. The galaxies are spread over an
unusually large area of ~12 Mpc with a velocity spread of ~4500 km/s. This
large-scale structure includes a highly asymmetric FRI radio galaxy and also
appears to host a radio relic. It may represent an unrelaxed system with
different sub-structures interacting or merging with one another. We discuss
the implications of these observations for future large-scale radio surveys.
