The JCMT BISTRO-2 Survey: Magnetic fields of the massive DR21 filament
Date
2022
Authors
Ching, Tao-Chung
Qiu, Keping
Li, Di
Ren, Zhiyuan
Lai, Shih-Ping
Berry, David
Pattle, Kate
Furuya, Ray
Ward-Thompson, Derek
Johnstone, Doug
Journal Title
Journal ISSN
Volume Title
Publisher
The Astrophysical Journal
Abstract
We present 850 μm dust polarization observations of the massive DR21 filament from the B-fields In STar-forming
Region Observations (BISTRO) survey, using the POL-2 polarimeter and the SCUBA-2 camera on the James
Clerk Maxwell Telescope. We detect ordered magnetic fields perpendicular to the parsec-scale ridge of the DR21
main filament. In the subfilaments, the magnetic fields are mainly parallel to the filamentary structures and
smoothly connect to the magnetic fields of the main filament. We compare the POL-2 and Planck dust polarization
observations to study the magnetic field structures of the DR21 filament on 0.1–10 pc scales. The magnetic fields
revealed in the Planck data are well-aligned with those of the POL-2 data, indicating a smooth variation of
magnetic fields from large to small scales. The plane-of-sky magnetic field strengths derived from angular
dispersion functions of dust polarization are 0.6–1.0 mG in the DR21 filament and ∼0.1 mG in the surrounding
ambient gas. The mass-to-flux ratios are found to be magnetically supercritical in the filament and slightly
subcritical to nearly critical in the ambient gas. The alignment between column density structures and magnetic
fields changes from random alignment in the low-density ambient gas probed by Planck to mostly perpendicular in
the high-density main filament probed by James Clerk Maxwell Telescope. The magnetic field structures of the
DR21 filament are in agreement with MHD simulations of a strongly magnetized medium, suggesting that
magnetic fields play an important role in shaping the DR21 main filament and subfilaments.
Description
Keywords
Interstellar magnetic fields, Star-forming regions, Interstellar filaments, Submillimetre astronomy, Polarimetry
Citation
Ching, T., Qiu, K., Li, D., Ren, Z., Lai, S., Berry, D., . . . van Loo, S. (2022). “The JCMT BISTRO-2 Survey: Magnetic fields of the massive DR21 filament.” The Astrophysical Journal, 941(122). https://doi.org/10.3847/1538-4357/ac9dfb