Sunyaev-Zel'dovich observations with AMI of the hottest galaxy clusters detected in the XMM-Newton Cluster Survey
Romer, A. Kathy; AMI Consortium; Olamaie, Malak; Rodríguez-Gonzálvez, Carmen; Feroz, Farhan; Franzen, Thomas M. O.; Grainge, Keith J. B.; Hobson, Michael P.; Hurley-Walker, Natasha; Lasenby, Anthony N.; Pooley, Guy G.; Saunders, Richard D. E.; Scaife, Anna M. M.; Scott, Paul F.; Shimwell, Timothy W.; Titterington, David J.; Waldram, Elizabeth M.; Lloyd-Davies, E. J.; Perrott, Yvette C.; Schammel, Michel P.; Rumsey, Clare
Australia, United States, United Kingdom
Abstract
We have obtained deep Sunyaev-Zel'dovich (SZ) observations towards 15 of the 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 10 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. Our upper limits on the cluster temperature of undetected systems are lower than the mean XCS derived temperature.