Description
The formation of massive stars is a violent, explosive process. Even before the start of the main sequence, massive stars can significantly alter their environments through HII regions and outflows that can reshape the surrounding gas and dust in the host molecular clouds. This can have consequences for future star formation in proximity to these early-type stars, potentially even leading to sequential star formation and further massive star formation. However, the wider effects of this on star formation rates and efficiency, as well as the role of magnetic fields in the process, is poorly understood at present. G34.26+0.15 is a hub-filament cloud at a distance of 3.3kpc and is part of the W48 complex. Its dense central hub contains multiple ultra-compact HII regions which have been extensively studied, indicative of massive star formation; these border an expanded HII region that appears to have substantially altered a portion of the cloud, potentially triggering massive star formation. We present an analysis of the magnetic field structure across the cloud, demonstrating how it has been substantially reshaped by the HII region, inferred from observations of polarised dust emission at 850um taken using the Submillimetre Common-User Bolometer Array-2 (SCUBA-2) and its polarimeter POL-2, mounted on the JCMT. We also present preliminary analysis of other similar expanded HII regions across the Milky Way at a similar distance, in order to investigate whether magnetic field alignment to HII region boundaries changes throughout their evolution.
