A pair of unequal jets imparted the kick velocity to the neutron star of Cassiopeia A

RESUMO

We analyze observations of the Cassiopeia A core-collapse supernova remnant (CCSNR) and identify a pair of opposite rings, attributing their formation to unequal-energy explosion jets that also imparted the neutron star (NS) its kick velocity via the kick-BEAP (kick by early asymmetrical pair of jets) mechanism. We replicate the formation of these ring structures, which we identify as circum-jet rings, with three-dimensional hydrodynamical simulations of two opposite explosion jets in which the northern jet is much more powerful, forming the larger northern ring known as the Crown. The line connecting the centers of the two opposite rings passes through the previously-established point-symmetric center of Cassiopeia A. The momentum difference between the two jets also explains the observed southwards NS kick velocity of ~400 km/s. The kick-BEAP and point-symmetric morphology suggest powering and shaping by several pairs of jets during the explosion process, strengthening the jittering jets explosion mechanism for the Cassiopeia A CCSNR and core-collapse supernovae in general.