Galactic winds play a crucial role in regulating star formation by expelling large amounts of cold, star-forming gas. The archetypal starburst galaxy M82 exhibits a superwind driven by intense star formation and supernova activity. Cold gas and dust persist throughout the wind, but the mechanism in which this material is transported to great distances without being destroyed by the hot wind remains unclear. In this study, we present high-resolution (2.5 pc) JWST NIRCam and MIRI images that capture polycyclic aromatic hydrocarbon (PAH) emission throughout the M82 wind. These images reveal intricate filamentary dust structures at 3.3, 7.7, and 11.3 microns. Ratios of these PAH features reveal clues into dust processing in the superwind, including grain size and ionization. We find a consistent increase in the 11.3/7.7 micron PAH ratio with distance from the starburst. The 3.3/7.7 and 3.3/11.3 ratios exhibit flatter distributions and remain relatively low in the extended wind. Altogether, these ratios indicate that PAH grains are larger and more neutral far from the dust-destroying radiation field generated by the starburst. These JWST images provide a stunning level of detail into the composition and structure of the cool phase of a starburst-driven superwind.
