Initial Conditions for Idealised Clusters Mergers, simulating El Gordo
  Simulations of isolated binary mergers of galaxy clusters are a useful tool
to study the evolution of these objects. For exceptionally massive systems they
even represent the only viable way of simulation, because these are rare in
typical cosmological simulations. We present a new practical model for these
simulations based on the Hernquist dark matter profile. The hydrostatic
equation is solved for a beta-model with $\beta$ = 2/3 in this potential and
approximate expressions for X-ray brightness and Compton-y parameter are
derived. We show in detail how to setup such a system using SPH. The
theoretical and several numerical models are compared to observed scaling
relations of galaxy clusters and satisfactory agreement with the self-similar
relations is found. The model is then applied to investigate the observed
cluster ACT-CT J0102-4915 (El Gordo), a particularly massive merging high
redshift cluster. We are able to reproduce the X-ray luminosity, SZ-effect and
dark matter core distance as well as the rough shape of the observed cluster
for reasonable model parameters. The lack of substruc- ture prevents us from
obtaining the fluctuations observed in the wake of the system and we argue that
the parent cluster of the system was highly disturbed even before the main
merger observed today.
