  Dynamical motions in the ICM can imprint distinctive features on X-ray images
that map the thermal emission from galaxy clusters, such as sharp surface
brightness discontinuities due to shocks and cold fronts. The gas dynamics
during cluster mergers may also drive large-scale turbulence in the ICM, which
in turn generates extended synchrontron sources known as radio halos. Surface
brightness edges have been found numerous times in the thermal gas of clusters
based on X-ray observations. In contrast, edges in radio halos have only been
observed in a handful of cases. Our goal is to search for new radio surface
brightness discontinuities in the ICM. We inspected the images of the Bullet
Cluster and the other 25 radio halos reported in the MeerKAT Galaxy Cluster
Legacy Survey. To aid the identification of surface brightness discontinuities,
we applied a gradient-filtering edge-detection method to the radio images. We
find that the adopted filtering technique is helpful in identifying surface
brightness edges in radio images, allowing us to identify at least one gradient
in half of the radio halos studied. For the Bullet Cluster, we find excellent
agreement between the locations of the 4 radio discontinuities detected and the
X-ray edges. This similarity informs us that there is substantial interplay
between thermal and nonthermal components in galaxy clusters. This interplay is
likely due to the frozen-in ICM magnetic field, which mediates the advection of
cosmic rays while being dragged by thermal gas flows. We conclude that radio
halos are shaped by dynamical motions in the ICM and that they often display
surface brightness discontinuities, which appear to be co-located with edges in
the thermal gas emission. Our results demonstrate that new and future
generations of radio telescopes will provide a complementary approach to X-rays
to efficiently detect shocks and cold fronts in the ICM.
