High-resolution radio observations of massive protostars in the SARAO MeerKAT Galactic Plane Survey

We present high-resolution observations made with the Australia Telescope Compact Array (ATCA) at 5.5 and 9.0 GHz of a sample of 28 massive protostars. These protostars were initially detected at radio wavelengths in the MeerKAT Galactic Plane Survey at 1.3 GHz, where they were unresolved with an angular resolution of approximately 8 arcsec. The resolution of the ATCA observations at 5.5 and 9.0 GHz is significantly higher at 2.0 and 1.2 arcsec, respectively. The highest angular resolution corresponds to a linear resolution of 1920 au for our nearest object. This improvement in resolution enabled us to resolve the components of extended emission and to more accurately determine the nature of the objects. Approximately 80 per cent of the detections were classified as jets, with 68 per cent of the jets found to be associated with non-thermal emission.