SOFIA observations of 30 Doradus: II -- Magnetic fields and large scale gas kinematics

Abstract

The heart of the Large Magellanic Cloud, 30 Doradus, is a complex region with a clear core-halo structure. Feedback from the stellar cluster R136 has been shown to be the main source of energy creating multiple pc-scale expanding-shells in the outer region, and carving a nebula core in the proximity of the ionization source. We present the morphology and strength of the magnetic fields (B-fields) of 30 Doradus inferred from the far-infrared polarimetric observations by SOFIA/HAWC+ at 89, 154, and 214$\mu$m. The B-field morphology is complex, showing bending structures around R136. In addition, we use high spectral and angular resolution [\textsc{CII}] observations from SOFIA/GREAT and CO(2-1) from APEX. The kinematic structure of the region correlates with the B-field morphology and shows evidence of multiple expanding shells. Our B-field strength maps, estimated using the Davis-Chandrasekhar-Fermi method and structure-function, show variations across the cloud within a maximum of 600, 450, and 350$\mu$G at 89, 154, and 214$\mu$m, respectively. We estimated that the majority of the 30 Doradus clouds are sub-critical and sub-Alfvénic. The probability distribution function of the gas density shows that the turbulence is mainly compressively driven, while the plasma beta parameter indicates supersonic turbulence. We show that the B-field is sufficient to hold the cloud structure integrity under feedback from R136. We suggest that supersonic compressive turbulence enables the local gravitational collapse and triggers a new generation of stars to form. The velocity gradient technique (VGT) using [\textsc{CII}] and CO(2-1) is likely to confirm these results.

26 pages, 17 figures, 3 tables, accepted to ApJ

References in corpus (27)

• Tracing Magnetic Fields with Aligned Grains
• On the Star Formation Efficiency of Turbulent Magnetized Clouds
• Early Science with SOFIA, the Stratospheric Observatory for Infrared Astronomy
• CO Isotopologues in the Perseus Molecular Cloud Complex: the X-Factor and Regional Variations
• What determines the density structure of molecular clouds ? A case study of Orion B with Herschel
• On the Structure of the Orion A Cloud and the Formation of the Orion Nebula Cluster
• Unfolding the Laws of Star Formation: The Density Distribution of Molecular Clouds
• A Problem with the Clustering of Recent Measures of the Distance to the Large Magellanic Cloud
• Velocity Gradients as a Tracer for Magnetic Fields
• Tracing interstellar magnetic field using velocity gradient technique: Application to Atomic Hydrogen data
• Expanding bubbles in Orion A: [CII] observations of M42, M43, and NGC 1977
• Gravity, Magnetic Field, and Turbulence: Relative Importance and Impact on Fragmentation in the Infrared Dark Cloud G34.43+00.24
• Magnetic Field Morphology in Interstellar Clouds with the Velocity Gradient Technique
• FEEDBACK: a SOFIA Legacy Program to Study Stellar Feedback in Regions of Massive Star Formation
• Effects of Magnetic Fields on Photoionised Pillars and Globules
• Understanding star formation in molecular clouds IV. Column density PDFs from quiescent to massive molecular clouds
• Magnetic fields in star formation: a complete compilation of all the DCF estimations
• On Internal and External Alignment of Dust Grains in Protostellar Environments
• The CO-dark molecular gas mass in 30 Doradus
• Mapping the magnetic field in the Taurus/B211 filamentary cloud with SOFIA HAWC+ and comparing with simulation
• Magnetic field strength from turbulence theory (I): Using differential measure approach (DMA)
• FEEDBACK from the NGC7538 HII region
• Dense gas formation in the Musca filament due to the dissipation of a supersonic converging flow
• Observations of magnetic fields surrounding LkH$\alpha$ 101 taken by the BISTRO survey with JCMT-POL-2
• The SOFIA FEEDBACK Legacy Survey: Dynamics and mass ejection in the bipolar HII region RCW 36
• HI-H${}_2$ transition: exploring the role of the magnetic field
• A new phase of massive star formation? A luminous outflow cavity centred on an infrared quiet core

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