Simulations of the merging galaxy cluster Abell 2034: what determines
  the level of separation between gas and dark matter
  Cluster mergers are an important laboratory for studying the behaviour of
dark matter (DM) and intracluster gas. There are dissociative collisions that
can separate the intracluster gas from the DM. Abell 2034 presents clear
dissociative features observed by X-rays and gravitational lensing. The
cluster, at $z$ = 0.114, consists of two substructures with mass ratio of about
1:2.2, separated by $\sim$720 kpc. The X-ray emission peak is offcentred from
the south DM peak by $\sim$350 kpc. Using N-body hydrodynamical simulations, we
aim to reconstruct the dynamic history of the collision, reproducing the
observed features, and also to explore the conditions that led to the
dissociation. Our best model assuming that the collision is close to the plane
of the sky, with a small impact parameter, observed 0.26 Gyr after central
passage, reproduces the observed features of this cluster, such as the offset
between X-ray and DM peaks, X-ray morphology and temperatures. We explored
several variations using different gas and DM concentrations for each cluster.
The level of dissociation was quantified by the distances between X-ray and DM
peaks, and also by the gas retention in the cluster cores. We found that the
ratio of central gas densities is more important than the ratio of central DM
densities in determining the level of dissociation.
