GALAXY CLUSTERS AT z ≥ 1: GAS CONSTRAINTS FROM THE SUNYAEV-ZEL'DOVICH ARRAY

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 similar to 10(13) M-circle dot, 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,M-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,M-X-ray to self-similar scaling relations between these observables determined from observations of lower redshift clusters, finding consistency given the measurement error.