Reverberation of the Vela PULSAR WIND NEBULA

Abstract

Transonic (withMach numberMs 1) motion of a pulsar relative to the external medium canhelp its compact pulsar wind nebula develop a double-torus X-ray morphology. The double-torus structurecan reverberate as a whole under the dynamic pressure of the external flow. For a flow aligned with thesymmetry axis of the nebula, the response of the double-torus is uniform in azimuth. For a misalignedflow, the leeward sides of the tori respond with some delay relative to their windward sides. The delay cancause a curious swaying in the short midsection of the leeward jet of the compact X-ray nebula. Within theframework of the relativisticmagnetohydrodynamical model of a pulsar wind nebula we study the dynamicsof the nebular outflows contributing to the swaying of the jet. When applied to the Vela X-ray nebula, themodel allows us to naturally relate two distinct phenomena, the swaying of the bright midsection of the Velalee jet and the reverberation of its double-torus.