We describe radio continuum and spectral line observations of the source G320.4–01.2 ( MSH 15–5 2 ) and the coincident young pulsar B1509–58 made with the Australia Telescope Compact Array .
Based on a comparison between X-ray and radio observations , we argue that the two main radio components of G320.4–01.2 are a single supernova remnant ( SNR ) , which H i absorption indicates is at a distance of 5.2 \pm 1.4 kpc .
A high-resolution correspondence between radio and X-rays argues that the pulsar is interacting with the SNR via an opposed pair of collimated outflows .
The outflow itself is seen as an elongated X-ray feature surrounded by a highly polarized radio sheath , while the interaction with the SNR manifests itself as a ring of radio/X-ray knots within the optical nebula RCW 89 .
We reject the hypothesis that the pulsar outflow powers the entire RCW 89 region .

SNR G320.4–01.2 and PSR B1509–58 agree in distance and in rotation measure , and appear to be interacting .
We thus conclude that the two objects are associated and have an age of \la 1700 yr. We propose that the SNR resulted from a high-energy or low-mass supernova which occurred near the edge of an elongated cavity .
Such a model can account for the SNR ’ s bilateral appearance , its large apparent age , the significant offset of the pulsar from the SNR ’ s centre and the faintness of the pulsar-powered nebula at radio wavelengths .