High & ultra-high energy cosmic ray acceleration in structure-formation shocks in Abell 3376 galaxy cluster

Abstract

We describemultiwavelength optical, X-ray and radio evidences of energeticmergers in southern galaxy cluster Abell 3376 (A3376, redshift z=0.046, X-ray luminosity "#$&'($' ( ). Here we report the rare discovery of gigantic, Mpc-scale non-thermal radio structures (‘radio-arcs’), shaped like a pair of bow-shock fronts on the merger axis. We argue for the shock acceleration origin of the radio emission and discuss the possibilty of acceleration of very high energy cosmic ray particles in this and similar clusters