We present 10 ^ { \prime \prime } to 18 ^ { \prime \prime } images of four massive clusters of galaxies through the Sunyaev-Zel ’ dovich Effect ( SZE ) .
These measurements , made at 90 GHz with the MUSTANG receiver on the Green Bank Telescope ( GBT ) , reveal pressure sub-structure to the intra-cluster medium ( ICM ) in three of the four systems .
We identify the likely presence of a previously unknown weak shock-front in MACS0744+3927 .
By fitting the Rankine-Hugoniot density jump conditions in a complementary SZE/X-ray analysis , we infer a Mach number of \mathcal { M } = 1.2 ^ { +0.2 } _ { -0.2 } and a shock-velocity of 1827 ^ { +267 } _ { -195 } km s ^ { -1 } .
In RXJ1347-1145 , we present a new reduction of previously reported data and confirm the presence of a south-east SZE enhancement with a significance of 13.9 \sigma when smoothed to 18 ^ { \prime \prime } resolution .
This too is likely caused by shock-heated gas produced in a recent merger .
In our highest redshift system , CL1226+3332 , we detect sub-structure at a peak significance of 4.6 \sigma in the form of a ridge oriented orthogonally to the vector connecting the main mass peak and a sub-clump revealed by weak lensing .
We also conclude that the gas distribution is elongated in a south-west direction , consistent with a previously proposed merger scenario .
The SZE image of the cool core cluster Abell 1835 is , in contrast , consistent with azimuthally symmetric signal only .
This pilot study demonstrates the potential of high-resolution SZE images to complement X-ray data and probe the dynamics of galaxy clusters .