We report our analysis of MACS J0717.5+3745 using 140 and 268 GHz Bolocam data collected at the Caltech Submillimeter Observatory .
We detect extended Sunyaev-Zel ’ dovich ( SZ ) effect signal at high significance in both Bolocam bands , and we employ Herschel -SPIRE observations to subtract the signal from dusty background galaxies in the 268 GHz data .
We constrain the two-band SZ surface brightness toward two of the sub-clusters of MACS J0717.5+3745 : the main sub-cluster ( named C ) , and a sub-cluster identified in spectroscopic optical data to have a line-of-sight velocity of +3200 km s ^ { -1 } ( named B ) .
We determine the surface brightness in two separate ways : via fits of parametric models and via direct integration of the images .
For both sub-clusters , we find consistent surface brightnesses from both analysis methods .
We constrain spectral templates consisting of relativistically corrected thermal and kinetic SZ signals , using a jointly-derived electron temperature from Chandra and XMM-Newton under the assumption that each sub-cluster is isothermal .
The data show no evidence for a kinetic SZ signal toward sub-cluster C , but they do indicate a significant kinetic SZ signal toward sub-cluster B .
The model-derived surface brightnesses for sub-cluster B yield a best-fit line-of-sight velocity of v _ { z } = +3450 \pm 900 km s ^ { -1 } , with ( 1 - \textrm { Prob } [ v _ { z } \geq 0 ] ) = 1.3 \times 10 ^ { -5 } ( 4.2 \sigma away from 0 for a Gaussian distribution ) .
The directly integrated sub-cluster B SZ surface brightnesses provide a best-fit v _ { z } = +2550 \pm 1050 km s ^ { -1 } , with ( 1 - \textrm { Prob } [ v _ { z } \geq 0 ] ) = 2.2 \times 10 ^ { -3 } ( 2.9 \sigma ) .