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arXiv · 2606.17262

Dust-Embedded Star Formation: Bridging Magellanic Cloud Studies of Massive Young Stellar Objects to Nearby Spiral Galaxies

M. Jimena Rodríguez·Rémy Indebetouw·Janice C. Lee·Bradley C. Whitmore·David A. Thilker·J. Peltonen·Erik Rosolowsky·Thomas G. Williams·Eric W. Koch·Bruce Elmegreen·Ralf S. Klessen·Roberta Paladini·Sumit Sarbadhicary·Daniel A. Dale·Kelsey E. Johnson·Aida Wofford
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Abstract

We use JWST NIRCam and MIRI imaging at 2, 4, 10, and 21 um to study young, dusty compact sources in four nearby galaxies at distances of ~ 1-5Mpc (M33, NGC300, NGC7793, and NGC5068). This work bridges well-characterized massive young stellar objects (MYSOs) in the Magellanic Clouds from the Spitzer SAGE survey to new studies of embedded clusters in more distant galaxies with JWST. Guided by the SAGE-LMC catalog, we define JWST color-magnitude selection criteria (F1000W versus F1000W-F2100W) and test them using resolution-degradation experiments. We identify 216, 32, 80 and 139 dusty young objects in the four galaxies, respectively. The selected population spans sources from systems dominated by a single MYSO to compact marginally resolved sources hosting multiple MYSOs. The color selection remains stable across 1-5 Mpc, and the 10um luminosity function retains a slope of alpha~ -2. However, blending and surface-brightness dilution remove fainter sources, leading to incompleteness of up to ~ 50% at 5.2 Mpc and biasing the sample toward brighter objects (F1000W < 19 mag). The sample spans approximate stellar masses of ~10-2 X 10^5 Mo. Spatial resolution affects the interpretation of mid-infrared emission: clustering increases the fraction of emission attributed to compact sources in active regions, while blending into diffuse emission dominates in quiescent environments. Comparisons with PAH-selected young clusters in the PHANGS galaxy NGC5068 show that our selection recovers ~ 80% of the PAH-selected sources. We show that the practical limit for studying individual MYSOs with JWST is ~3 Mpc. The resulting catalog provides a foundation for future resolved studies of star formation rates and early cluster evolution.

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M. Jimena Rodríguez, Rémy Indebetouw, Janice C. Lee, Bradley C. Whitmore, David A. Thilker, J. Peltonen, Erik Rosolowsky, Thomas G. Williams, Eric W. Koch, Bruce Elmegreen, Ralf S. Klessen, Roberta Paladini, Sumit Sarbadhicary, Daniel A. Dale, Kelsey E. Johnson, Aida Wofford. 2026-06-15. Dust-Embedded Star Formation: Bridging Magellanic Cloud Studies of Massive Young Stellar Objects to Nearby Spiral Galaxies. https://arxiv.org/abs/2606.17262

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