NUMERICAL SIMULATIONS OF ROTATING COOLING FLOWS IN GALAXY CLUSTER ENVIRONMENTS

We have used 2D numerical simulations to study the evolution of galaxy cluster cooling flows undergoing a rotational perturbation. We show t hat such rotations in the intracluster medium may arise from cluster/s ubcluster mergers. Our galaxy cluster initial conditions involve spher ically symmetric, steady-state cooling flows with varying mass-dropout strengths. The rotational perturbation serves to break the symmetry f or each of the initial cooling flows, resulting in the formation of th in, gaseous disc-like structure extending radially out to similar to 1 0 kpc. Disc-like structure formed for low mass-dropout strength simula tions appears to contain cooling condensations whereas disc-like struc ture in higher mass-dropout strength simulations appears smooth. This is due to the influence of mass-dropout on the degree of cooling, whic h serves to reduce the strength of thermal instabilities by the remova l of 'cold' gas from the flow. Morphological comparisons of the disc-l ike structure formed in our simulations are made to structure observed in the X-ray emitting gas of A4059. Comparisons of the gas dynamics w ithin the disc-like structure are also made to the solid-body rotation profile observed from emission-line gas within the central galaxy of Hydra A. The influence of grid effects on the simulations is also disc ussed.