Numerical Simulations of Merging Clusters of Galaxies and their Observational Consequences.

Previous abstract Next abstract

Session 95 -- Substructures of Galaxy Clusters, Field Galaxies
Oral presentation, Wednesday, 11, 1995, 2:00pm - 3:30pm

[95.01D] Numerical Simulations of Merging Clusters of Galaxies and their Observational Consequences.

K. Roettiger, J.O. Burns, C. Loken (NMSU)

In recent years, it has become apparent through various substructure analyses that galaxy clusters are not necessarily the virialized, hydrostatic systems once assumed. Observations indicate an active history of cluster mergers that appears to continue into the current epoch. As the value of galaxy clusters as cosmological probes has become more fully recognized, it has become increasingly important that we understand the dynamical state of clusters and the influence of cluster dynamics on the various cluster observables. To this end, we have conducted, under controlled conditions, a parameter study of cluster mergers using a hybrid Eulerian Hydrodynamical/N-body code in which the gaseous intracluster medium, as represented by the fluid equations, is evolved self-consistently within the gravitational potential defined by the cluster dark matter, represented by the N-body particle distribution. Our parameter space consists of relative cluster dynamical mass and gas richness. Some of our results include a large degree of expansion and elongation in the gas distribution relative to the dark matter distribution and large-scale (100's of kpc), sustained bulk flows as the gas sloshes about within the gravitational potential. We also find that although evidence of the merger persists for 5 Gyrs or more, the most dramatic consequences fade on time scales of ~2 Gyrs. I will further discuss the evolution of mergers and their effect on cluster observations. Included in this discussion will be X-ray derived estimates of dynamical mass and baryonic fraction.

Wednesday program listing