On stability of toroidal structures in two-tori pulsar wind nebulae

Abstract

Abstract The effect of weakly supersonic flow on two-tori pulsar wind nebula is considered. It is shown that the flow going past the nebula does not destroy its two-tori structure, but, on the contrary, contributes to its stability. Under the effect of the flow, the windward and the leeward polar outflows in the nebula operate at drastically different conditions. In the result, two opposite jets of the nebula which form within these polar outflows may differ in their dynamics and appearance. Our work bears implications for the Vela pulsar wind nebula, which interacts with a supersonic flow of Mach number ∼ 1.3 produced by the reverse shock of its parent supernova.