Magnetic fields in the massive star-forming region NGC 6334 and their relationship with the properties of dust filaments probed by [CII] and PAH emissions

Abstract

We carried out the near-infrared ($JHK_{\rm s}$) imaging polarimetric observation with the polarimeter SIRPOL on the Infrared Survey Facility (IRSF) 1.4 m telescope and [CII] line mapping observation with a Fabry-P\'{e}rot spectrometer on board a 100-cm TIFR balloon-borne far-infrared telescope toward NGC 6334, and revealed the relationship between the plane-of-sky (POS) magnetic fields and [CII] emission lines to investigate the star formation in the molecular cloud. The polarization vector map shows that the POS magnetic fields are approximately perpendicular to the main filament elongation of NGC 6334. On the other hand, the POS magnetic fields tend to be parallel or random for the other filaments in NGC 6334. The [CII] emission shows a distribution well aligned with the main filament. Strong [CII] emission is also seen in the hub-filament system. Since the main filament is sandwiched between two HII regions, it is most likely that gas is efficiently accreting from the shells of the HII regions along the magnetic field resulting in active star formation. This is consistent with the NGC 6334 being bright in [CII] emission.