Surveying the Giant HII Regions of the Milky Way with SOFIA: VIII. W43 Main

TL;DR

This study provides a detailed multi-wavelength analysis of W43 Main, a massive star-forming region in the Milky Way, revealing that its star formation activity is typical compared to other Galactic HII regions despite its unique environment.

Contribution

It offers a comprehensive multi-wavelength characterization of W43 Main, including SED fitting and evolutionary analysis, highlighting its star formation activity as consistent with average Galactic HII regions.

Findings

20 compact infrared objects identified, 80% are MYSOs or candidates

W43 Main's star formation metrics are median values for Galactic HII regions

Despite its location at a spiral arm and Galactic Bar junction, star formation activity is typical

Abstract

In this eighth paper of the SOFIA-FORCAST series on Milky Way GHII regions, we present an analysis of the massive star-forming complex W43 Main. We compared our 11 - 37 micron maps with multi-wavelength observations from the near-infrared to radio, and investigated the physical nature of compact sources and dust substructures. We applied SED 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 objects (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 GHII region.