Interferometric Mapping of Magnetic Fields: The massive star forming region G34.4+0.23 MM

TL;DR

This study uses millimeter interferometry to map magnetic fields in the massive star forming region G34.4+0.23 MM, revealing a uniform polarization pattern aligned with the filament, indicative of a magnetically supported disk structure.

Contribution

First detailed interferometric polarization observations of G34.4+0.23 MM, showing magnetic field morphology aligned with the filament structure.

Findings

Magnetic fields are aligned with the filament's main axis.

Polarization patterns are uniform across dust and CO emission.

Magnetic support likely influences the disk structure.

Abstract

We report millimeter interferometric observations of polarized continuum and line emission from the massive star forming region G34.4. Polarized thermal dust emission at 3 mm wavelength and CO $J=1 \to 0$ line emission were observed using the Berkeley-Illinois-Maryland Association (BIMA) array. Our results show a remarkably uniform polarization pattern in both dust and in CO J=$1 \to 0$ emission. In addition, the line emission presents a consistent uniform polarization pattern over most of the velocity channel maps. These uniform polarization patterns are aligned with the north-south main axis of the filament between the main millimeter source (MM) and the ultra-compact H {\scriptsize II} region, which are the central sources in G34.4, suggesting a magnetic field orthogonal to this axis. This morphology is consistent with a magnetically supported disk seen roughly edge-on.