Galaxy Clusters at z >= 1: Gas Constraints from the Sunyaev-Zel'dovich Array
Andreon, S.; Carlstrom, J. E.; Leitch, E. M.; Pryke, C.; Stanford, S. A.; Bulbul, E.; Maughan, B.; Marrone, D. P.; Bonamente, M.; Mroczkowski, T.; Joy, M.; Culverhouse, T. L.; Muchovej, S.; Greer, C.; Gralla, M. B.; Hasler, N.; Hawkins, D.; Hennessy, R.; Jetha, N. N.; Lamb, J. W.; Miller, A.; Sharp, M.; Woody, D.
United States, Italy, United Kingdom
Abstract
We present gas constraints from Sunyaev-Zel'dovich (SZ) effect measurements in a sample of 11 X-ray and infrared (IR) selected galaxy clusters at z>=1, using data from the Sunyaev-Zel'dovich Array (SZA). The cylindrically integrated Compton-y parameter, Y, is calculated by fitting the data to a two-parameter gas pressure profile. Where possible, we also determine the temperature of the hot intracluster plasma from Chandra and XMM-Newton data and constrain the gas mass within the same aperture (r 2500) as Y. The SZ effect is detected in the clusters for which the X-ray data indicate gas masses above ~1013 M sun, including XMMU J2235 - 2557 at redshift z = 1.39, which to date is one of the most distant clusters detected using the SZ effect. None of the IR-selected targets are detected by the SZA measurements, indicating low gas masses for these objects. For these and the four other undetected clusters, we quote upper limits on Y and M gas,SZ, with the latter derived from scaling relations calibrated with lower redshift clusters. We compare the constraints on Y and X-ray-derived gas mass M gas,X-ray to self-similar scaling relations between these observables determined from observations of lower redshift clusters, finding consistency given the measurement error.