A Multiwavelength Dynamical State Analysis of ACT-CL J0019.6+0336

Denisha S Pillay,Kabelo C Kesebonye,Sinenhlanhla P Sikhosana,Nadeem Oozeer,Kenda Knowles,Tony Mroczkowski,Kavilan Moodley,Edward J Wollack,David J Turner,Christoph Pfrommer,Matt Hilton

doi:10.3390/galaxies9040097

Abstract

In our study, we show a multiwavelength view of ACT-CL J0019.6+0336 (which hosts a radio halo), to investigate the cluster dynamics, morphology, and ICM. We use a combination of XMM-Newton images, Dark Energy Survey (DES) imaging and photometry, SDSS spectroscopic information, and 1.16 GHz MeerKAT data to study the cluster properties. Various X-ray and optical morphology parameters are calculated to investigate the level of disturbance. We find disturbances in two X-ray parameters and the optical density map shows elongated and axisymmetric structures with the main cluster component southeast of the cluster centre and another component northwest of the cluster centre. We also find a BCG offset of ∼950 km/s from the mean velocity of the cluster, and a discrepancy between the SZ mass, X-ray mass, and dynamical mass (MX,500 and MSZ,500 lies >3σ away from Mdyn,500), showing that J0019 is a merging cluster and probably in a post-merging phase.

Highlights

Multiwavelength observations of galaxy clusters carry an abundance of information, giving insight into the intracluster medium (ICM), its thermal and non-thermal components, and the cluster dynamics
To compare our optical results to the literature, the above methods were applied to a sample of 98 galaxy clusters found in Wen and Han [34], with known cluster dynamical states
We find that galaxy clusters with an asymmetry value, A2 > 0.1 or a centre shift value, CS > 0.4 are all dynamically disturbed

Summary

Introduction

Multiwavelength observations of galaxy clusters carry an abundance of information, giving insight into the intracluster medium (ICM), its thermal and non-thermal components, and the cluster dynamics. Turbulence in the ICM affects individual sources in the cluster, radio galaxies [2]. Most radio emissions from galaxies have a compact radio source associated with the active galactic nuclei (AGN) and extended regions of radio emission (radio lobes) quite distant from the compact radio source. The morphology of extended radio emission associated with individual galaxies (such as bent tail galaxies) is strongly influenced by the environment in which the galaxy exists [3]. The motion of galaxy clusters through the dense cluster gas is widely recognized as the mechanism which produces bent radio source tails and the dynamic pressure responsible for a variety of other observed source shapes [3]

Results

Discussion

Conclusion