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

TL;DR

This study uses high-resolution radio observations with ATCA to resolve and analyze the structure of massive protostars initially detected in the MeerKAT survey, revealing detailed jet features and emission types.

Contribution

It provides the first high-resolution radio imaging of these protostars, improving understanding of their emission mechanisms and jet structures compared to prior unresolved observations.

Findings

80% of protostars show jet-like features

68% of jets exhibit non-thermal emission

Resolution achieved down to 1920 AU for nearest objects

Abstract

We present high-resolution observations made with the Australia Telescope Compact Array (ATCA) at 5.5 GHz and 9.0 GHz of a sample of twenty-eight 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 arcseconds. The resolution of the ATCA observations at 5.5 GHz and 9.0 GHz are significantly higher at, 2.0 and 1.2 arc seconds, 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% of the detections were classified as jets with 68% of the jets found to be associated with non-thermal emission.