Simulating nearly edge-on sloshing in the galaxy cluster Abell 2199

Abstract

Off-axis collisions between galaxy clusters may induce the phenomenon of sloshing, causing dense gas to be dragged from the cool core of a cluster, resulting in a spiral of enhanced X-ray emission. Abell 2199 displays signatures of sloshing in its core and it is possible that the orbital plane of the collision is seen nearly edge-on. We aim to evaluate whether the features of Abell 2199 can be explained by a sloshing spiral seen under a large inclination angle. To address this, we perform tailored hydrodynamical $N$-body simulations of a non-frontal collision with a galaxy group of $M_{200}=1.6\times10^{13}\,{\rm M_{\odot}}$. We obtain a suitable scenario in which the group passed by the main cluster core 0.8 Gyr ago, with a pericentric separation of 292 kpc. Good agreement is obtained from the temperature maps as well as the residuals from a $\beta$-model fit to the simulated X-ray emission. We find that under an inclination of $i=70^{\circ}$ the simulation results remain consistent with the observations.