HIGH ANGULAR RESOLUTION OBSERVATION OF THE SUNYAEV-ZEL'DOVICH EFFECT IN THE MASSIVE z ≈ 0.83 CLUSTER Cl J0152-1357

X-ray observations of galaxy clusters at high redshift (z greater than or similar to 0.5) indicate that they are more morphologically complex and less virialized than those at low redshift. We present the first subarcminute resolution synthesis observations at 18 GHz of the Sunyaev-Zel'dovich (SZ) effect for Cl J0152-1357 using the Australia Telescope Compact Array. Cl J0152-1357 is a massive cluster at redshift z = 0.83 and has a complex structure including several merging subclumps which have been studied at optical, X-ray, and radio wavelengths. Our high-resolution observations indicate a clear displacement of the maximum SZ effect from the peak of X-ray emission for the most massive subclump. This result shows that the cluster gas within the cluster substructures is not virialized in Cl J0152-1357, and we suggest that it is still recovering from a recent merger event. A similar offset of the SZ effect has recently been seen in the bullet cluster and in RX J1347-1145. This non-equilibrium situation implies that high-resolution observations are necessary to investigate galaxy cluster evolution and to extract cosmological constraints from a comparison of the SZ effect and X-ray signals.