Some results on the radio-SZ correlation for galaxy cluster radio halos
  We present correlation results for the radio halo power in galaxy clusters
with the integrated thermal Sunyaev-Zel'dovich (SZ) effect signal, including
new results obtained at sub-GHz frequencies. The radio data is compiled from
several published works, and the SZ measurements are taken from the Planck ESZ
cluster catalog. The tight correlation between the radio halo power and the SZ
effect demonstrates a clear correspondence between the thermal and non-thermal
electron populations in the intra-cluster medium, as already has been shown in
X-ray based studies. The radio power varies roughly as the square of the global
SZ signal, but when the SZ signal is scaled to within the radio halo radius the
correlation becomes approximately linear, with reduced intrinsic scatter. We do
not find any strong indication of a bi-modal division in the radio halo cluster
population, as has been reported in the literature, which suggests that such
duality could be an artifact of X-ray selection. We compare the SZ signal
dependence of radio halos with simplified predictions from theoretical models,
and discuss some implications and shortcomings of the present work.
