A MULTI-WAVELENGTH STUDY OF THE SUNYAEV―ZEL'DOVICH EFFECT IN THE TRIPLE-MERGER CLUSTER MACS J0717.5+3745 WITH MUSTANG AND BOLOCAM

We present 90, 140, and 268 GHz subarcminute resolution imaging of the Sunyaev-Zel'dovich effect (SZE) in the disturbed, intermediate-redshift (z = 0.5458) galaxy cluster MACS J0717.5+3745, a triple-merger system comprising four distinct, optically detected subclusters. Our 90 GHz SZE data result in a sensitive, 34 [mu]Jy beam super(-1) map of the SZE at 13" effective resolution using the MUSTANG bolometer array on the Green Bank Telescope (GBT). MUSTANG also detects pressure substructure that is not well constrained by the Chandra X-ray data in the remnant core of a merging subcluster. We find that the small-scale pressure enhancements in the MUSTANG data amount to ~2% of the total pressure measured in the 140 GHz Bolocam observations. Repeating this analysis using flux densities measured directly from our maps results in a 3.4% probability v sub(z) [< or =, slant] 0. We note that this tantalizing result for the kinetic SZE is on resolved, subcluster scales.