Evolution of shocks and turbulence in the formation of galaxy clusters
  embedded in Megaparsec-scale filaments
  Massive structures like cluster of galaxies, embedded in cosmic filaments,
release enormous amount of energy through their interactions. These events are
associated with production of Mpc-scale shocks and injection of considerable
amount of turbulence, affecting the non-thermal energy budget of the ICM. In
order to study this thoroughly, we performed a set of cosmological simulations
using the hydrodynamical code Enzo. We studied the formation of clusters
undergoing major mergers, the propagation of merger shocks and their
interaction with the filamentary cosmic web. This interaction is shown to
produce peripheral structures remarkably similar to giant radio relics
observed, for example, in Abell 3376 and Abell 3667. We find a relatively long
timescale (about 4 Gyr) for turbulence decay in the centre of major merging
clusters. This timescale is substantially longer than typically assumed in the
turbulent re-acceleration models, invoked for explaining the statistics of
observed radio halos.
