Polarized Light from Massive Protoclusters (POLIMAP). I. Dissecting the Role of Magnetic Fields in the Massive Infrared Dark Cloud G28.37+0.07
Journal article, 2024
Magnetic fields may play a crucial role in setting the initial conditions of massive star and star cluster formation. To investigate this, we report SOFIA-HAWC+ 214 μm observations of polarized thermal dust emission and high-resolution GBT-Argus C18O(1-0) observations toward the massive Infrared Dark Cloud (IRDC) G28.37+0.07. Considering the local dispersion of B-field orientations, we produce a map of the B-field strength of the IRDC, which exhibits values between ∼0.03 and 1 mG based on a refined Davis-Chandrasekhar-Fermi method proposed by Skalidis & Tassis. Comparing to a map of inferred density, the IRDC exhibits a B-n relation with a power-law index of 0.51 ± 0.02, which is consistent with a scenario of magnetically regulated anisotropic collapse. Consideration of the mass-to-flux ratio map indicates that magnetic fields are dynamically important in most regions of the IRDC. A virial analysis of a sample of massive, dense cores in the IRDC, including evaluation of magnetic and kinetic internal and surface terms, indicates consistency with virial equilibrium, sub-Alfvénic conditions, and a dominant role for B-fields in regulating collapse. A clear alignment of magnetic field morphology with the direction of the steepest column density gradient is also detected. However, there is no preferred orientation of protostellar outflow directions with the B-field. Overall, these results indicate that magnetic fields play a crucial role in regulating massive star and star cluster formation, and therefore they need to be accounted for in theoretical models of these processes.
Author
Chi Yan Law
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
European Southern Observatory (ESO)
Jonathan Tan
University of Virginia
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
R. Skalidis
California Institute of Technology (Caltech)
Larry Morgan
Green Bank Observatory
Duo Xu
University of Virginia
Felipe de Oliveira Alves
Institute of Space Sciences (ICE) - CSIC
Ashley T. Barnes
European Southern Observatory (ESO)
Natalie Butterfield
Green Bank Observatory
P. Caselli
Max Planck Society
Giuliana Cosentino
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Francesco Fontani
Arcetri Astrophysical Observatory
Jonathan D. Henshaw
Liverpool John Moores University
I. Jimenez-Serra
Instituto Nacional de Tecnica Aeroespacial
Wanggi Lim
California Institute of Technology (Caltech)
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 967 2 157Subject Categories
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
Fusion, Plasma and Space Physics
DOI
10.3847/1538-4357/ad39e0