We present Combined Array for Research in Millimeter-wave Astronomy ( CARMA ) observations of a massive galaxy cluster discovered in the Arcminute Microkelvin Imager ( AMI ) blind Sunyaev-Zel ’ dovich ( SZ ) survey .
Without knowledge of the cluster redshift a Bayesian analysis of the AMI , CARMA and joint AMI & CARMA uv -data is used to quantify the detection significance and parameterise both the physical and observational properties of the cluster whilst accounting for the statistics of primary CMB anisotropies , receiver noise and radio sources .
The joint analysis of the AMI & CARMA uv -data was performed with two parametric physical cluster models : the \beta -model ; and the model described in Olamaie , Hobson , & Grainge 31 with the pressure profile fixed according to ( 3 ) .
The cluster mass derived from these different models is comparable but our Bayesian evidences indicate a preference for the \beta -profile which we , therefore , use throughout our analysis .
From the CARMA data alone we obtain a formal Bayesian probability of detection ratio of 12.8:1 when assuming that a cluster exists within our search area ; alternatively assuming that Jenkins et al . 24 accurately predicts the number of clusters as a function of mass and redshift , the formal Bayesian probability of detection is 0.29:1 .
From the Bayesian analysis of the AMI or AMI & CARMA data the probability of detection ratio exceeds 4.5 \times 10 ^ { 3 } :1 .
Performing a joint analysis of the AMI & CARMA data with a physical cluster model we derive the total mass internal to r _ { 200 } as M _ { T, 200 } = 4.1 \pm 1.1 \times 10 ^ { 14 } M _ { \odot } .
Using a phenomenological \beta -model to quantify the temperature decrement as a function of angular distance we find a central SZ temperature decrement of 170 \pm 24 \mu K in the AMI & CARMA data .
The SZ decrement in the CARMA data is weaker than expected and we speculate that this is a consequence of the cluster morphology .
In a forthcoming study the pipeline that we have developed for the analyses of these data will be used to thoroughly assess the impact of cluster morphology on the SZ decrements that are observed with interferometers such as AMI and CARMA .