SIMBAD references

Shock fronts produced in galaxy cluster mergers are commonly used to infer the dynamical conditions of the collision, including the relative velocity of the clusters. In this work we investigate how the initial infall velocity affects the strength of merger shocks in unequal-mass systems. We perform idealized hydrodynamical simulations of cluster mergers with a mass ratio of 1:10 and initial approach velocities ranging from 0 to 3000 km s^–1. The Mach number and temperature of the shock fronts are measured after core passage during the outgoing phase of the merger. We find that both quantities vary only weakly across the explored velocity range, with shocks consistently exhibiting ${ \mathcal M }\sim 2$-3 and temperatures of ∼7-9 keV. These results indicate that, for highly unequal-mass mergers, shock strength is not very sensitive to the initial approach velocity.