We report measurements of the Sunyaev-Zel ’ dovich ( SZ ) effect in three high-redshift ( 0.89 \leq z \leq 1.03 ) , X-ray selected galaxy clusters .
The observations were obtained at 30 GHz during the commissioning period of a new , eight-element interferometer – the Sunyaev-Zel ’ dovich Array ( SZA ) – built for dedicated SZ effect observations .
The SZA observations are sensitive to angular scales larger than those subtended by the virial radii of the clusters .
Assuming isothermality and hydrostatic equilibrium for the intracluster medium , and gas-mass fractions consistent with those for clusters at moderate redshift , we calculate electron temperatures , gas masses , and total cluster masses from the SZ data .
The SZ-derived masses , integrated approximately to the virial radii , are 1.9 ^ { +0.5 } _ { -0.4 } \times 10 ^ { 14 } M _ { \odot } for Cl J1415.1+3612 , 3.4 ^ { +0.6 } _ { -0.5 } \times 10 ^ { 14 } M _ { \odot } for Cl J1429.0+4241 and 7.2 ^ { +1.3 } _ { -0.9 } \times 10 ^ { 14 } M _ { \odot } for Cl J1226.9+3332 .
The SZ-derived quantities are in good agreement with the cluster properties derived from X-ray measurements .