2025ApJ...989..221Z

We present high-resolution radio observations of the pulsar wind nebula (PWN) MSH 15-52, which is renowned for its distinctive handlike shape, and its associated supernova remnant RCW 89. Using the Australia Telescope Compact Array, we obtained 3 and 6 cm radio maps with a resolution of 2″. These unveil small-scale radio features in the system and allow a direct comparison with the arcsecond-resolution X-ray images. We find that the radio emission is composed of a complex filamentary structure. In particular, there is a bar-like feature across the central pulsar B1509-58 in the inner PWN, and the radio sheath wrapping around the pulsar also appears to be made up of filaments. Some prominent X-ray features are not detected in radio, including the one-sided jet in the south and the fingerlike structures in the north. These indicate turnover of the particle distribution at low energies in these regions. For RCW 89, the radio emission well coincides with both the X-ray knots and the Hα filaments. The high polarization fraction shows that the emission is synchrotron in nature, but it extends well beyond the sharp boundary of the nonthermal X-ray emission, which is difficult to explain.