Simulations of gas sloshing induced by a newly discovered gas poor
  substructure in galaxy cluster Abell 1644
  Collision events lead to peculiar morphologies in the intracluster gas of
galaxies clusters. That seems to be the case of Abell 1644, a nearby galaxy
cluster, composed of three main structures: the southern cluster that exhibits
a spiral-like morphology, A1644S; the northern cluster seen in X-ray
observations, A1644N1; and the recently discovered substructure, A1644N2. By
means of $N$-body hydrodynamical simulations, we attempt to reconstruct the
dynamical history of this system. These simulations resulted in two specific
scenarios: (i) The collision between A1644S and A1644N2. Our best model has an
inclination between the merger plane and the plane of the sky of $30^\circ$,
and reaches the best morphology $1.6\,$Gyr after the pericentric passage. At
this instant A1644N2 is gas poor, becoming nearly undetectable in X-ray
emission. This model shows a good agreement with observations; (ii) The
collision between A1644S and A1644N1. This approach did not give rise to
results as satisfactory as the first scenario, due to great disturbances in
density and mismatching temperature maps. As a complementary study, we perform
a three-cluster simulation using as base the best-fitting model to reproduce
the current state of A1644 with the three main structures. This scenario
presented a good agreement to the global morphology of the observations. Thus,
we find that the more likely scenario is a collision between A1644S and the
newly discovered A1644N2, where A1644N1 may be present as long as it does not
greatly interfere in the formation of the spiral feature.
