JCMT BISTRO Observations: Magnetic Field Morphology of Bubbles Associated with NGC 6334

TL;DR

This study analyzes magnetic field morphologies around HII regions in NGC 6334 using polarization data, revealing gas and magnetic field interactions, and proposes methods for identifying bubble impacts on magnetic fields in star-forming regions.

Contribution

It provides new insights into magnetic field structures around bubbles in NGC 6334 and introduces computer vision techniques for future bubble identification.

Findings

Magnetic fields are pushed away from bubbles, showing tangential patterns.

In dense regions, magnetic fields remain unaffected by HII regions.

Nested polarization patterns reveal bipolar structures in bubbles.

Abstract

We study the HII regions associated with the NGC 6334 molecular cloud observed in the sub-millimeter and taken as part of the B-fields In STar-forming Region Observations (BISTRO) Survey. In particular, we investigate the polarization patterns and magnetic field morphologies associated with these HII regions. Through polarization pattern and pressure calculation analyses, several of these bubbles indicate that the gas and magnetic field lines have been pushed away from the bubble, toward an almost tangential (to the bubble) magnetic field morphology. In the densest part of NGC 6334, where the magnetic field morphology is similar to an hourglass, the polarization observations do not exhibit observable impact from HII regions. We detect two nested radial polarization patterns in a bubble to the south of NGC 6334 that correspond to the previously observed bipolar structure in this bubble. Finally, using the results of this study, we present steps (incorporating computer vision; circular Hough Transform) that can be used in future studies to identify bubbles that have physically impacted magnetic field lines.