Located at z = 0.203, A2163 is a rich galaxy cluster with an intra-clustermedium (ICM) that exhibits extraordinary properties, including an exceptionallyhigh X-ray luminosity, average temperature, and a powerful and extended radiohalo. The irregular and complex morphology of its gas and galaxy structuresuggests that this cluster has recently undergone major merger events thatinvolve two or more cluster components. In this paper, we study the gasstructure and dynamics by means of spectral-imaging analysis of X-ray dataobtained from XMM-Newton and Chandra observations. From the evidence of a coldfront, we infer the westward motion of a cool core across the E-W elongatedatmosphere of the main cluster A2163-A. Located close to a galaxy over-density,this gas 'bullet' appears to have been spatially separated from its galaxy (andpresumably dark matter component) as a result of high-velocity accretion.  From gas brightness and temperature profile analysis performed in twoopposite regions of the main cluster, we show that the ICM has beenadiabatically compressed behind the crossing 'bullet' possibly because of shockheating, leading to a strong departure of the ICM from hydrostatic equilibriumin this region. Assuming that the mass estimated from the Yx proxy bestindicates the overall mass of the system and that the western cluster sector isin approximate hydrostatic equilibrium before subcluster accretion, we infer amerger scenario between two subunits of mass ratio 1:4, leading to a presenttotal system mass of M500 $\propto 1.9 \times 1015 M_{\odot}$. The exceptionalproperties of A2163 present various similarities with those of 1E0657-56, theso-called 'bullet-cluster'. These similarities are likely to be related to acomparable merger scenario.

A2163: Merger events in the hottest Abell galaxy cluster II. Subcluster accretion with galaxy-gas separation