The JCMT BISTRO Survey: Evidence for Pinched Magnetic Fields in Quiescent Filaments of NGC 1333

Abstract

We investigate the internal 3D magnetic structure of dense interstellar filaments within NGC 1333 using polarization data at $850\mu \mathrm{m}$ from the $B$-fields In STar-forming Region Observations survey at the James Clerk Maxwell Telescope. Theoretical models predict that the magnetic field lines in a filament will tend to be dragged radially inward (i.e., pinched) toward the central axis due to the filament's self-gravity. We study the cross-sectional profiles of the total intensity ($I$) and polarized intensity (PI) of dust emission in four segments of filaments unaffected by local star formation that are expected to retain a pristine magnetic field structure. We find that the filaments' FWHM in PI are not the same as those in $I$, with two segments being appreciably narrower in PI (FWHM ratio $\simeq 0.7-0.8$) and one segment being wider (FWHM ratio $\simeq 1.3$). The filament profiles of the polarization fraction ($P$) do not show a minimum at the spine of the filament, which is not in line with an anticorrelation between $P$ and $I$ normally seen in molecular clouds and protostellar cores. Dust grain alignment variation with density cannot reproduce the observed $P$ distribution. We demonstrate numerically that the $I$ and PI cross-sectional profiles of filaments in magnetohydrostatic equilibrium will have differing relative widths depending on the viewing angle. The observed variations of FWHM ratios in NGC 1333 are therefore consistent with models of pinched magnetic field structures inside filaments, and especially if they are magnetically near-critical or supercritical.

arXiv commentAccepted for publication in ApJL

References in corpus (32)

• Astropy: A Community Python Package for Astronomy
• The Spitzer c2d Legacy Results: Star Formation Rates and Efficiencies; Evolution and Lifetimes
• Characterizing interstellar filaments with Herschel in IC5146
• Radiative torques: Analytical Model and Basic Properties
• Magnetic Fields in the Formation of Sun-Like Stars
• SCUBA-2: on-sky calibration using submillimetre standard sources
• A Large Catalog of Accurate Distances to Local Molecular Clouds: The Gaia DR2 Edition
• From Filamentary Networks to Dense Cores in Molecular Clouds: Toward a New Paradigm for Star Formation
• Characterizing the properties of nearby molecular filaments observed with Herschel
• The Gould's Belt Distances Survey (GOBELINS). V. Distances and Kinematics of the Perseus molecular cloud
• The JCMT BISTRO Survey: The magnetic field strength in the Orion A filament
• Magnetically regulated collapse in the B335 protostar ? I. ALMA observations of the polarized dust emission
• Polarized Sub-Millimetre Emission from Filamentary Molecular Clouds
• Mapping Distances Across the Perseus Molecular Cloud Using CO Observations, Stellar Photometry, and Gaia DR2 Parallax Measurements
• The Magnetic Field Morphology of the Class 0 Protostar L1157-mm
• Fibers in the NGC1333 proto-cluster
• High-resolution Ultraviolet Radiation Fields of Classical T Tauri Stars
• 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
• Magnetohydrostatic Equilibrium Structure and Mass of Filamentary Isothermal Cloud Threaded by Lateral Magnetic Field
• Highly Ordered and Pinched Magnetic Fields in the Class 0 Proto-Binary System L1448 IRS 2
• Grain alignment and disruption by radiative torques in dense molecular clouds and implication for polarization holes
• The JCMT BISTRO Survey: Magnetic Fields Associated with a Network of Filaments in NGC 1333
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. XII. The Perseus YSO Population as Observed with IRAC and MIPS
• Physical properties of the ambient medium and of dense cores in the Perseus star-forming region derived from Herschel Gould Belt Survey observations
• Understanding the origin of the magnetic field morphology in the wide-binary protostellar system BHR 71
• Modeling Dust Polarization Observations of Molecular Clouds through MHD Simulations
• Magnetic fields in star forming systems (I): Idealized synthetic signatures of dust polarization and Zeeman splitting in filaments
• A Magnetic Ribbon Model for Star-Forming Filaments
• Distortion of Magnetic Fields in a Starless Core II: 3D Magnetic Field Structure of FeSt 1-457
• Magnetohydrostatic Equilibrium Structure and Mass of Polytropic Filamentary Cloud Threaded by Lateral Magnetic Field
• Feedback of molecular outflows from protostars in NGC 1333, revealed by Herschel and Spitzer spectro-imaging observations
• Fitting an Analytic Magnetic Field to a Prestellar Core

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• The JCMT BISTRO-2 Survey: Magnetic Fields of the Massive DR21 Filament
• Triple spiral arms of a triple protostar system imaged in molecular lines
• The spatial correlation between CN line and dust continuum emitting regions in high-mass star-forming cloud
• The factors that influence protostellar multiplicity I: Gas temperature, density, and mass in Perseus with Nobeyama
• Unveiling the role of magnetic fields in an accreting filament onto a young protocluster
• The Impact of Expanding HII Regions on Filament G37:Curved Magnetic Field and Multiple Direction Material Flows
• The factors that influence protostellar multiplicity II. Gas temperature and mass in Perseus with APEX