Coude, S;
Bastien, P;
Houde, M;
Sadavoy, S;
Friesen, R;
Di Francesco, J;
Johnstone, D;
... Zhu, L; + view all
(2019)
The JCMT BISTRO Survey: The Magnetic Field of the Barnard 1 Star-forming Region.
Astrophysical Journal
, 877
(2)
, Article 88. 10.3847/1538-4357/ab1b23.
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Abstract
We present the POL-2 850 μm linear polarization map of the Barnard 1 clump in the Perseus molecular cloud complex from the B-fields In STar-forming Region Observations survey at the James Clerk Maxwell Telescope. We find a trend of decreasing polarization fraction as a function of total intensity, which we link to depolarization effects toward higher-density regions of the cloud. We then use the polarization data at 850 μm to infer the plane-of-sky orientation of the large-scale magnetic field in Barnard 1. This magnetic field runs north–south across most of the cloud, with the exception of B1-c, where it turns more east–west. From the dispersion of polarization angles, we calculate a turbulence correlation length of 5.0 ± 2farcs5 (1500 au) and a turbulent-to-total magnetic energy ratio of 0.5 ± 0.3 inside the cloud. We combine this turbulent-to-total magnetic energy ratio with observations of NH3 molecular lines from the Green Bank Ammonia Survey to estimate the strength of the plane-of-sky component of the magnetic field through the Davis–Chandrasekhar–Fermi method. With a plane-of-sky amplitude of 120 ± 60 μG and a criticality criterion λ c = 3.0 ± 1.5, we find that Barnard 1 is a supercritical molecular cloud with a magnetic field nearly dominated by its turbulent component.
Type: | Article |
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Title: | The JCMT BISTRO Survey: The Magnetic Field of the Barnard 1 Star-forming Region |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.3847/1538-4357/ab1b23 |
Publisher version: | https://doi.org/10.3847/1538-4357/ab1b23 |
Language: | English |
Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, ISM: clouds, ISM: individual objects (Barnard 1), ISM: magnetic fields, polarization, stars: formation, submillimeter: ISM, GOULD BELT SURVEY, RADIATIVE TORQUES, INTERSTELLAR GRAINS, MOLECULAR CLOUDS, POLARIZATION MEASUREMENTS, INFRARED POLARIMETRY, LINEAR-POLARIZATION, H2O MASERS, SCUBA-2, ALIGNMENT |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10078589 |
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