Resolving the Merging Planck Cluster PLCK G147.3-16.6 with GISMO

Abstract

The $Planck$ satellite has recently completed an all-sky galaxy cluster survey exploiting the thermal Sunyaev-Zel'dovich (SZ) effect to locate some of the most massive systems observable. With a median redshift of $⟨z⟩=0.22$, the clusters found by $Planck$ at $z>0.3$ are proving to be exceptionally massive and/or disturbed systems. One notable $Planck$ discovery at $z=0.645$, PLCK G147.3-16.6, has a dual core and hosts a radio halo, indicating it is likely in the process of merging. We present a 16."5 resolution SZ observation of this high-$z$ merger using the Goddard-IRAM Superconducting 2 Millimeter Observer (GISMO), and compare it to X-ray follow-up observations with XMM-$Newton$. We find the SZ pressure substructure is offset from the core components seen in X-ray. We interpret this offset as possible line of sight temperature or density substructure due to the on-going merger.

6 pages, 4 figures, 1 table. Accept for publication in ApJ Letters (9 June 2015)