MeerKAT view of the diffuse radio sources in Abell 3667 and their
  interactions with the thermal plasma
  During their lifetime, galaxy clusters grow through the accretion of matter
from the filaments of the large scale structure and from mergers with other
clusters. These mergers release a large amount of energy into the intracluster
medium (ICM) through merger shocks and turbulence. These phenomena are
associated with the formation of radio sources known as radio relics and radio
halos, respectively. Radio relics and halos are unique proxies to study the
complex properties of these dynamically active regions of clusters and in
general the micro physics of the ICM. Abell 3667 is a spectacular examples of a
merging system hosting a large pair of radio relics. Due to its proximity
(z=0.0553) and large mass, the system enables the study of these sources to a
uniquely high level of detail. We observed Abell 3667 with MeerKAT as part of
the MeerKAT Galaxy Cluster Legacy Survey. We used these data to study the large
scale emission of the cluster, including its polarisation and spectral
properties. We present the most detailed view of the radio relic system in
Abell 3667 to date, with a resolution reaching 3 kpc. The relics are filled
with a network of filaments with different spectral and polarisation properties
that are likely associated with multiple regions of particle acceleration and
local enhancements of the magnetic field. Conversely, the magnetic field in the
space between filaments has strengths close to that expected in unperturbed
regions at the same cluster-centric distance. Comparisons with MHD simulations
supports the idea of filaments as multiple acceleration sites. Our observations
also confirm the presence of an elongated radio halo, developed in the wake of
the bullet-like sub-cluster that merged from the South-East. Finally, we
associate the process of magnetic draping to a thin polarised radio source
surrounding the remnant of the bullet's cool core.
