Sunyaev-Zel'dovich observations of LoCuSS clusters with the Arcminute Microkelvin Imager: high X-ray luminosity sample

TL;DR

This study uses the Arcminute Microkelvin Imager to observe high X-ray luminosity galaxy clusters, detecting the Sunyaev-Zel'dovich effect in most, and deriving cluster parameters that reveal discrepancies at higher temperatures.

Contribution

First SZ observations of high X-ray luminosity clusters with AMI, deriving cluster parameters and comparing SZ and X-ray temperatures to explore their relationship.

Findings

SZ effect detected in 7 out of 8 clusters

Good agreement between SZ and X-ray temperatures at low TX

Discrepancy observed at TX above 6 keV

Abstract

We present observations from the Small Array of the Arcminute Microkelvin Imager (AMI) of eight high X-ray luminosity galaxy cluster systems selected from the Local Cluster Substructure Survey (LoCuSS) sample.We detect the Sunyaev-Zel'dovich (SZ) effect in seven of these clusters. With the assumptions that galaxy clusters are isothermal, have a density profile described by a spherical b -model and obey the theoretical M-T relation, we are able to derive cluster parameters at r200 from our SZ data. With the additional assumption of hydrostatic equilibrium we are able to derive parameters at r500. We present posterior probability distributions for cluster parameters such as mass, radius and temperature (TSZ, MT). Combining our sample with that of AMI Consortium: Rodr'\iguez-Gonz\'alvez et al. (2011) and using large-radius X-ray temperature estimates (TX) from Chandra and Suzaku observations, we find that there is reasonable correspondence between TX and TSZ,MT values at low TX, but that for clusters with TX above around 6keV the correspondence breaks down with TX exceeding TSZ, MT; we stress that this finding is based on just ten clusters.