Deep radio observations of the radio halo of the bullet cluster 1E
  0657-55.8
  We present deep 1.1-3.1 GHz Australia Telescope Compact Array observations of
the radio halo of the bullet cluster, 1E 0657-55.8. In comparison to existing
images of this radio halo the detection in our images is at higher
significance. The radio halo is as extended as the X-ray emission in the
direction of cluster merger but is significantly less extended than the X-ray
emission in the perpendicular direction. At low significance we detect a faint
second peak in the radio halo close to the X-ray centroid of the smaller
sub-cluster (the bullet) suggesting that, similarly to the X-ray emission, the
radio halo may consist of two components. Finally, we find that the distinctive
shape of the western edge of the radio halo traces out the X-ray detected bow
shock. The radio halo morphology and the lack of strong point-to-point
correlations between radio, X-ray and weak-lensing properties suggests that the
radio halo is still being formed. The colocation of the X-ray shock with a
distinctive radio brightness edge illustrates that the shock is influencing the
structure of the radio halo. These observations support the theory that shocks
and turbulence influence the formation and evolution of radio halo synchrotron
emission.
