A Cluster Merger and the Origin of the Extended Radio Emission in Abell 3667

Abstract

We present a numerical model for the extended steep-spectrum radio sources and the elongated X-ray structure in A3667 based on new three-dimensional MHD/ N -body simulations. The X-ray and optical analyses of A3667 indicate that it has undergone a recent subcluster merger event. We believe that the Mpc-scale radio sources identified in A3667 are also a consequence of the merger. Our previous numerical simulations show that mergers often produce large-scale shocks and turbulence capable of both magnetic field amplification and in situ reacceleration of relativistic particles. Our model suggests that these radio structures, separated by ~2.6 h -1 100 Mpc, are in fact causally linked via a slightly off-axis merger that occurred nearly in the plane of the sky approximately 1 Gyr ago with a subcluster having a total mass equal to ~20% of the primary cluster.