Submillimetre observations of the two-component magnetic field in M82. Issue 1 (13th May 2021)

• Record Type: Journal Article
• Authors: Pattle, Kate; Gear, Walter; Redman, Matt; Smith, Matthew W L; Greaves, Jane
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 505:Issue 1(2021)
• Page Start: 684
• Page End: 688
• Publication Date: 2021-05-13
• Subjects: galaxies: individual: M82 -- galaxies: magnetic fields -- submillimetre: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab1300
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We observed the starburst galaxy M82 in 850 µm polarized light with the POL-2 polarimeter on the James Clerk Maxwell Telescope (JCMT). We interpret our observed polarization geometry as tracing a two-component magnetic field: a poloidal component aligned with the galactic 'superwind', extending to a height ∼350 pc above and below the central bar; and a spiral-arm-aligned, or possibly toroidal, component in the plane of the galaxy, which dominates the 850 µm polarized light distribution at galactocentric radii ≳2 kpc. Comparison of our results with recent High-resolution Airborne Wideband Camera Plus (HAWC+) measurements of the field in the dust entrained by the M82 superwind suggests that the superwind breaks out from the central starburst at ∼350 pc above the plane of the galaxy.