2026ApJ..1000..136D

In this eighth paper of the Stratospheric Observatory For Infrared Astronomy-FORCAST series on Milky Way GH II regions, we present an analysis of the massive star-forming complex W43 Main. We compared our 11-37 μm maps with multiwavelength observations from the near-infrared to radio, and investigated the physical nature of compact sources and dust substructures. We applied spectral energy distribution fitting to constrain properties of the compact infrared objects, and examined the evolutionary states of the extended subregions. We identified 20 compact infrared objects, 16 (80%) of which we classify as massive young stellar object candidates (MYSOs) or candidate MYSOs. W43 Main resides at the junction of the Scutum spiral arm and the Galactic Bar, a location where enhanced turbulence is anticipated and has been proposed as a potential influence on star formation activity. Nevertheless, our analysis shows that its Lyman continuum photon production rate, the mass of its most massive MYSO, and its MYSO density are all consistent with the survey-wide median values. We therefore conclude that, despite W43 Main's unique Galactic environment, its present star formation activity appears broadly consistent with that of an average Galactic GH II region.