2024ApJ...963...94N

In this work, we present spectra of 11 young stellar objects (YSOs) taken with the Mid-Infrared Instrument / Medium Resolution Spectroscopy (MRS) instrument on board the James Webb Space Telescope (JWST). The YSOs are located in the N79 region of the Large Magellanic Cloud (LMC), an active star-forming region with hundreds of Spitzer- and Herschel-identified YSOs and host to super star cluster (SSC) candidate H72.97-69.39. The three giant molecular clouds in N79 (East, West, and South) have varying star formation rates and stellar populations. MRS follow-up observations of four Spitzer-identified YSOs in N79 East, West, and South have revealed that what seemed to be a single, massive YSO is actually a cluster of YSOs. We discuss the emission and absorption lines of six YSOs that have complete or almost-complete spectral coverage from 4.9-27.9 μm. YSO Y3, located in N79 East, is the youngest source in this study and likely to be less than 10,000 yr old, as inferred from the prominent CH₄, NH₃, CH₃OH, CH₃OCHO, and CO₂ ice absorption features. The most luminous source is the central ionizing YSO of SSC H72.97-69.39, Y4, which has dozens of fine-structure and H₂ emission lines. Unlike the other YSOs in this work, Y4 has no polyaromatic hydrocarbon emission lines, due to the intense ionizing radiation destroying these large carbon-chain molecules. The mass accretion rates based on the H I (7-6) line luminosities of YSOs Y1, Y2, Y4, and Y9 range between 1.22 × 10^–4-1.89 × 10^–2M_⊙ yr^–1. For the first time in the mid-infrared, we are able to resolve individual high-mass protostars forming in small clusters in an extragalactic environment like the LMC.