Dust polarized emission observations of NGC 6334; BISTRO reveals the details of the complex but organized magnetic field structure of the high-mass star-forming hub-filament network

Abstract

[Abridged] Filaments and hubs have received special attention recently thanks to studies showing their role in star formation. While the column density and velocity structures of both filaments and hubs have been studied, their magnetic fields (B-field) are not yet characterized. We aim to understand the role of the B-field in the dynamical evolution of the NGC 6334 hub-filament network. We present new observations of the dust polarized emission at 850$\mu$m towards NGC 6334 obtained with the JCMT/POL-2. We study the distribution and dispersion of the polarized intensity ($PI$), the polarization fraction ($PF$), and the B-field angle (${\theta }_B$). We derive the power spectrum of the intensity and ${\theta }_B$ along the ridge crest. Our analyses show a complex B-field structure when observed over the whole region ($\sim 10$ pc), however, at smaller scales ($\sim 1$ pc), ${\theta }_B$ varies coherently along the filaments. The observed power spectrum of ${\theta }_B$ can be well represented with a power law function with a slope $-1.33\pm 0.23$, which is $\sim 20\%$ shallower than that of $I$. This result is compatible with the properties of simulated filaments and may indicate the processes at play in the formation of filaments. ${\theta }_B$ rotates from being mostly perpendicular to the filament crests to mostly parallel as they merge with the hubs. This variation of ${\theta }_B$ may be tracing local velocity flows of matter in-falling onto the hubs. Our analysis suggests a variation of the energy balance along the crests of these filaments, from magnetically critical/supercritical at their far ends to magnetically subcritical near the hubs. We detect an increase of $PF$ towards the high-column density star cluster-forming hubs that may result from the increase of grain alignment efficiency due to stellar radiation from the newborn stars.

Accepted for publication in Astronomy & Astrophysics

References in corpus (31)

• MAMBO Mapping of Spitzer c2d Small Clouds and Cores
• Filamentary structure of star-forming complexes
• Radiative torques: Analytical Model and Basic Properties
• Planck intermediate results. XIX. An overview of the polarized thermal emission from Galactic dust
• Tracing Magnetic Fields with Aligned Grains
• SCUBA-2: iterative map-making with the Sub-Millimetre User Reduction Facility
• Magnetic Fields and Massive Star Formation
• Studies of regular and random magnetic fields in the ISM: statistics of polarization vectors and the Chandrasekhar-Fermi technique
• Placing Confidence Limits on Polarization Measurements
• The Efficiency of Grain Alignment in Dense Interstellar Clouds: A Reassessment of Constraints from Near Infrared Polarization
• Unifying low and high mass star formation through density amplified hubs of filaments
• Chains of dense cores in the Taurus L1495/B213 complex
• Large-scale filaments associated with Milky Way spiral arms
• Properties of the dense core population in Orion B as seen by the Herschel Gould Belt survey
• Grain Alignment by Radiative Torques in Special Conditions and Implications
• Filamentary Accretion Flows in the Infrared Dark Cloud G14.225-0.506 Revealed by ALMA
• Magnetized filamentary gas flows feeding the young embedded cluster in Serpens South
• Grain Alignment in Starless Cores
• Results of SPARO 2003: Mapping Magnetic Fields in Giant Molecular Clouds
• The JCMT BISTRO Survey: The Magnetic Field of the Barnard 1 Star-Forming Region
• The JCMT BISTRO Survey: Magnetic Fields Associated with a Network of Filaments in NGC 1333
• Probing fragmentation and velocity sub-structure in the massive NGC 6334 filament with ALMA
• Formation of the Musca filament: Evidence for asymmetries in the accretion flow due to a cloud-cloud collision
• Massive Clumps in the NGC 6334 Star Forming Region
• Formation of the Hub-Filament System G33.92+0.11: Local Interplay between Gravity, Velocity, and Magnetic Field
• A statistical analysis of dust polarization properties in ALMA observations of Class 0 protostellar cores
• Physical Properties of the star-forming clusters in NGC 6334
• Magnetized converging flows towards the hot core in the intermediate/high-mass star-forming region NGC 6334 V
• The role of Galactic HII regions in the formation of filaments. High-resolution submilimeter imaging of RCW 120 with ArTéMiS
• Bow Magnetic Morphology Surrounding Filamentary Molecular Clouds? 3D Magnetic Field Structure of Orion-A
• Quantifying the interplay between gravity and magnetic field in molecular clouds - a possible multi-scale energy equipartition in NGC6334

Cited by in corpus (48)

• Does the magnetic field suppress fragmentation in massive dense cores?
• Magnetic fields in star formation: a complete compilation of all the DCF estimations
• Filament coalescence and hub structure in MonR2: Implications to massive star and cluster formation
• 3D magnetic field morphology of the Perseus molecular cloud
• The JCMT BISTRO Survey: The Distribution of Magnetic Field Strengths towards the OMC-1 Region
• A cold accretion flow onto one component of a multiple protostellar system
• B-fields in Star-Forming Region Observations (BISTRO): Magnetic Fields in the Filamentary Structures of Serpens Main
• Magnetic Fields in Massive Star-Forming Regions (MagMaR) II. Tomography Through Dust and Molecular Line Polarization in NGC 6334I(N)
• The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2
• The JCMT BISTRO-2 Survey: Magnetic Fields of the Massive DR21 Filament
• Multi-scale physical properties of NGC 6334 as revealed by local relative orientations between magnetic fields, density gradients, velocity gradients, and gravity
• Velocity structure of the 50 pc-long NGC 6334 filamentary cloud: Hints of multiple compressions and their impact on the cloud properties?
• JCMT BISTRO Observations: Magnetic Field Morphology of Bubbles Associated with NGC 6334
• The SOFIA FEEDBACK Legacy Survey: Dynamics and mass ejection in the bipolar HII region RCW 36
• B-fields And dust in interstelLar fiLAments using Dust POLarization (BALLAD-POL): I. The massive filament G11.11-0.12 observed by SOFIA/HAWC+
• SOFIA observations of 30 Doradus: I -- Far-Infrared dust polarization and implications for grain alignment and disruption by radiative torques
• The Magnetic Field in the Milky Way Filamentary Bone G47
• A Multi-Scale Picture of Magnetic Field and Gravity from Large-Scale Filamentary Envelope to Core-Accreting Dust Lanes in the High-Mass Star-Forming Region W51
• The widths of magnetised filaments in molecular clouds
• The JCMT BISTRO Survey: Evidence for Pinched Magnetic Fields in Quiescent Filaments of NGC 1333
• Evolution of the Angular Momentum of Molecular Cloud Cores Formed from Filament Fragmentation
• The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43
• AFGL 5180 and AFGL 6366S: sites of hub-filament systems at the opposite edges of a filamentary cloud
• Evolution of the Hub-filament Structures in IC 5146 in the Context of the Energy Balance of Gravity, Turbulence, and Magnetic Field
• Three-dimensional magnetic fields of molecular clouds
• Magnetic Fields and Fragmentation of Filaments in the Hub of California-X
• The Role of Magnetic Fields in the Stability and Fragmentation of Filamentary Molecular Clouds: Two Case Studies at OMC-3 and OMC-4
• IC 5146 dark Streamer: is a first reliable candidate of edge collapse, hub-filament systems, and intertwined sub-filaments?
• Magnetic fields and outflows in the large Bok globule CB 54
• Emergence of high-mass stars in complex fiber networks (EMERGE) V. From filaments to spheroids: the origin of the hub-filament systems
• The Role of Magnetic Fields in the Formation of the Filamentary Infrared Dark Cloud G11.11-0.12
• Relative alignment between gas structures and magnetic field in Orion A at different scales using different molecular gas tracers
• Simulation of Head-on Collisions Between Filamentary Molecular Clouds Threaded by a Lateral Magnetic Field and Subsequent Evolution
• A Tale of Three: Magnetic Fields along the Orion Integral-Shaped Filament as Revealed by JCMT BISTRO survey
• Ionising feedback from an O star formed in a shock-compressed layer
• Deviation from a Continuous and Universal Turbulence Cascade in NGC 6334 due to Massive Star Formation Activity
• Different molecular filament widths as tracers of accretion onto filaments
• Line emission from filaments in molecular clouds
• A systematic bias in fitting the surface-density profiles of interstellar filaments
• The Formation of Filaments and Dense cores in the Cocoon Nebula (IC~5146)
• Evolution of magnetized hub-filament systems: Comparing the observed properties of W3(OH), W3 Main, and S 106
• A multi-scale view of the magnetic field morphology in the hot molecular core G31.41+0.31
• Dust destruction by the supernova remnant forward shock in a turbulent interstellar medium
• The Impact of Expanding HII Regions on Filament G37:Curved Magnetic Field and Multiple Direction Material Flows
• Evolution of compressed clouds formed by filament coalescence. I. Oblique collisions
• Evidence for the gravity-driven and magnetically-regularized gas flows feeding the massive protostellar cluster in Cepheus A
• The influence of magnetic fields in Cloud-Cloud Collisions
• A complete survey of filaments in Cygnus X