SZ observations with AMI of the hottest galaxy clusters detected in the
  XMM-Newton Cluster Survey
  We have obtained deep SZ observations towards 15 of the apparently hottest
XMM Cluster Survey (XCS) clusters that can be observed with the Arcminute
Microkelvin Imager (AMI). We use a Bayesian analysis to quantify the
significance of our SZ detections. We detect the SZ effect at high significance
towards three of the clusters and at lower significance for a further two
clusters. Towards the remaining ten clusters, no clear SZ signal was measured.
We derive cluster parameters using the XCS mass estimates as a prior in our
Bayesian analysis. For all AMI-detected clusters, we calculate large-scale mass
and temperature estimates while for all undetected clusters we determine upper
limits on these parameters. We find that the large- scale mean temperatures
derived from our AMI SZ measurements (and the upper limits from null
detections) are substantially lower than the XCS-based core-temperature
estimates. For clusters detected in the SZ, the mean temperature is, on
average, a factor of 1.4 lower than temperatures from the XCS. For clusters
undetected in SZ, the average 68% upper limit on the mean temperature is a
factor of 1.9 below the XCS temperature.
