A Parameter Space Exploration of Galaxy Cluster Mergers I: Gas Mixing and the Generation of Cluster Entropy

Understand

We present a high-resolution set of adiabatic binary galaxy cluster merger simulations using FLASH.

• These are the highest-resolution simulations to date of such mergers using an AMR grid-based code with Eulerian hydrodynamics.
• In this first paper in a series we investigate the effects of merging on the entropy of the hot intracluster gas, specifically with regard to the ability of merging to heat and disrupt cluster "cool-cores." We find, in line with recent works, that the effect of fluid instabilities that are well-resolved in grid-based codes is to significantly mix the gases of the two clusters and to significantly increase the entropy of the gas of the final merger remnant.
• This result is characteristic of mergers over a range of initial mass ratio and impact parameter.