We present 90 , 140 , and 268 GHz sub-arcminute 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 ^ { -1 } map of the SZE at 13 ^ { \prime \prime } effective resolution using the MUSTANG bolometer array on the Green Bank Telescope ( GBT ) .
Our 140 and 268 GHz SZE imaging , with resolutions of 58 ^ { \prime \prime } and 31 ^ { \prime \prime } and sensitivities of 1.8 and 3.3 mJy beam ^ { -1 } , respectively , was obtained through observations from the Caltech Submillimeter Observatory using Bolocam .
We compare these maps to a two-dimensional pressure map derived from Chandra X-ray observations .
Our MUSTANG SZE data confirm previous indications from Chandra of a pressure enhancement due to shock-heated , \gtrsim 20 { keV } gas immediately adjacent to extended radio emission seen in low-frequency radio maps of this cluster .
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 \sim 2 % of the total pressure measured in the 140 GHz Bolocam observations .
The X-ray inferred pseudo-pressure template also fails on larger scales to accurately describe the Bolocam data , particularly at the location of the subcluster with a remnant core known to have a high line of sight optical velocity of \sim 3200 km s ^ { -1 } .
Our Bolocam data are adequately described when we add an additional component—not described by a thermal SZE spectrum—to the X-ray template coincident with this subcluster .
Using flux densities extracted from our model fits , and marginalizing over the X-ray spectroscopic temperature constraints for the region , we fit a thermal + kinetic SZE spectrum to our Bolocam data and find that the subcluster has a best-fit line-of-sight proper velocity v _ { z } = 3600 ^ { +3440 } _ { -2160 } km s ^ { -1 } , in agreement with the optical velocity estimates for the subcluster .
The probability v _ { z } \leq 0 given our measurements is 2.1 % .
Repeating this analysis using flux densities measured directly from our maps results in a 3.4 % probability v _ { z } \leq 0 .
We note that this tantalizing result for the kinetic SZE is on resolved , subcluster scales .