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

TL;DR

This paper presents high-resolution SZ and X-ray observations of the merging galaxy cluster PLCK G147.3-16.6, revealing pressure substructure offset from X-ray cores, indicative of ongoing merger dynamics.

Contribution

First high-resolution SZ imaging of a high-redshift merging galaxy cluster with detailed comparison to X-ray data, uncovering merger-induced substructure.

Findings

SZ pressure substructure offset from X-ray cores

Evidence of ongoing merger activity

Line of sight temperature or density variations

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 $\left<z\right>=0.22$, 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.