Polarization observations reveal dominant toroidal magnetic fields of a few milligauss in a protostellar outflow, sufficient to collimate it and supporting magneto-centrifugal launching.
The JCMT BISTRO Survey: The magnetic field strength in the Orion A filament
7 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
We determine the magnetic field strength in the OMC 1 region of the Orion A filament via a new implementation of the Chandrasekhar-Fermi method using observations performed as part of the James Clerk Maxwell Telescope (JCMT) B-Fields In Star-Forming Region Observations (BISTRO) survey with the POL-2 instrument. We combine BISTRO data with archival SCUBA-2 and HARP observations to find a plane-of-sky magnetic field strength in OMC 1 of $B_{\rm pos}=6.6\pm4.7$ mG, where $\delta B_{\rm pos}=4.7$ mG represents a predominantly systematic uncertainty. We develop a new method for measuring angular dispersion, analogous to unsharp masking. We find a magnetic energy density of $\sim1.7\times 10^{-7}$ Jm$^{-3}$ in OMC 1, comparable both to the gravitational potential energy density of OMC 1 ($\sim 10^{-7}$ Jm$^{-3}$), and to the energy density in the Orion BN/KL outflow ($\sim 10^{-7}$ Jm$^{-3}$). We find that neither the Alfv\'{e}n velocity in OMC 1 nor the velocity of the super-Alfv\'{e}nic outflow ejecta is sufficiently large for the BN/KL outflow to have caused large-scale distortion of the local magnetic field in the $\sim$500-year lifetime of the outflow. Hence, we propose that the hour-glass field morphology in OMC 1 is caused by the distortion of a primordial cylindrically-symmetric magnetic field by the gravitational fragmentation of the filament and/or the gravitational interaction of the BN/KL and S clumps. We find that OMC 1 is currently in or near magnetically-supported equilibrium, and that the current large-scale morphology of the BN/KL outflow is regulated by the geometry of the magnetic field in OMC 1, and not vice versa.
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First velocity-resolved [O I] 63/145 um maps of the Orion BN/KL outflow show broad components from dense warm postshock gas, with line ratios matching 30-40 km/s dissociative J-shocks illuminated by external UV, yielding [O I] luminosity 86.5 L_sun and mass-loss rate ~9e-3 M_sun/yr.
Observational study of MBM12 shows CO-to-H2 conversion factor near galactic average with density-dependent variations, high virial parameters decreasing at small scales, broken power-law mass-size relations indicating external pressure, and magnetic field orientation transition at N(H2) = 4.5e21 cm-
High-resolution magnetic field maps of M17 SW reveal gravity-dominated energy budget with magnetic fields regulating collapse and accretion channels in a near-equipartition state.
RAT alignment boosted by B-star radiation plus DG alignment reproduces super-Serkowski spectra in HD 30614 and HD 204827 while standard RAT alone fits Serkowski spectra in HD 37903 and HD 161056.
The paper presents predictions and observational plans for Zeeman effect measurements with SKA to provide statistical data on magnetic field strengths across scales in molecular clouds.
Review summarizing observational data on the Milky Way's magnetic field structure, including spiral alignment, halo components, turbulence, and correlations with interstellar gas and dust.
citing papers explorer
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Unveiling Dominant Toroidal Magnetic Fields in a Protostellar Outflow
Polarization observations reveal dominant toroidal magnetic fields of a few milligauss in a protostellar outflow, sufficient to collimate it and supporting magneto-centrifugal launching.
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Velocity-resolved [O I] 63,145 um, [C II] 158 um, and OH mapping along the Orion BN/KL explosive outflow and irradiated shocks
First velocity-resolved [O I] 63/145 um maps of the Orion BN/KL outflow show broad components from dense warm postshock gas, with line ratios matching 30-40 km/s dissociative J-shocks illuminated by external UV, yielding [O I] luminosity 86.5 L_sun and mass-loss rate ~9e-3 M_sun/yr.
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B-Fields and Star Formation across Scales with TRAO (B-FROST): CO Abundances, Dynamics and Relative Orientations in the Translucent High Latitude Cloud MBM12
Observational study of MBM12 shows CO-to-H2 conversion factor near galactic average with density-dependent variations, high virial parameters decreasing at small scales, broken power-law mass-size relations indicating external pressure, and magnetic field orientation transition at N(H2) = 4.5e21 cm-
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BISTRO Survey: Gravity-Dominated and Magnetically Regulated Star Formation in M17 SW
High-resolution magnetic field maps of M17 SW reveal gravity-dominated energy budget with magnetic fields regulating collapse and accretion channels in a near-equipartition state.
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Grain Alignment and Dust Evolution Physics with Polarisation (GRADE-POL). II. On the physical basis of Serkowski and super-Serkowski polarisation spectra
RAT alignment boosted by B-star radiation plus DG alignment reproduces super-Serkowski spectra in HD 30614 and HD 204827 while standard RAT alone fits Serkowski spectra in HD 37903 and HD 161056.
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Measuring Magnetic Field Strengths in Galactic Star-forming Regions via the Zeeman Effect with the SKA
The paper presents predictions and observational plans for Zeeman effect measurements with SKA to provide statistical data on magnetic field strengths across scales in molecular clouds.
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The magnetic field of the Milky Way: an observational perspective
Review summarizing observational data on the Milky Way's magnetic field structure, including spiral alignment, halo components, turbulence, and correlations with interstellar gas and dust.