Simulations of Galaxy Cluster Mergers with Self-Interacting Dark Matter: Effects on the X-ray Emitting Gas
Abstract
Galaxy cluster mergers are the most energetic events in the current universe. The matter contained in clusters falls into three main categories: dark matter, gas, and stars, each of which has decidedly different collisional properties that are revealed by the spatial separations between the components after a cluster merger (as is seen in the Bullet Cluster). We run hydrodynamical/N-body simulations of head-on cluster mergers using the AREPO code, modeling all three matter types with varying dark matter self-interaction cross sections. This allows us to determine the effect that dark matter has on the observable properties of baryonic matter (stars and gas) in the merging clusters due to changes in the gravitational potential, including separations in position and velocity space. The latter will be observable in the near future with new X-ray observatories with microcalorimeters, such as XRISM, Athena, and Lynx, which will be able to measure the line of sight velocity of the intra-cluster medium. We simulate a number of potential collision scenarios by varying the mass ratio of the clusters and the initial velocity of their collision. With this data we may constrain dark matter cross sections by comparing observed stellar and gas velocities to ones from simulated mergers with known dark matter collisionality.
- Publication:
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American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23537124M