Speaker
Description
The star formation process is at the center of the baryonic cycle, dictating galaxy evolution and setting the stage for planet formation. Feedback from massive stars injects momentum, energy and metals into the natal cloud, kickstarting the emergence process of young star clusters. JWST can pierce through the dusty interstellar medium and reveal the feedback-driving emerging young star clusters (eYSCs).
I will present the initial analysis of a portion of our pilot NIRSpec/MOS observations in NGC628, as part of the FEAST (Feedback in Emerging extrAgalactic Star clusTers) program. With spectroscopy in the 1-5um range, we can probe the ionization and stellar content of eYSCs (He and H recombination lines), the properties of photodissociation regions (PDRs) with H2 and polycyclic aromatic hydrocarbon (PAH) emission, and single out the active stellar feedback mechanisms via line diagnostics. We find that the eYSCs are indeed at a young, energetic evolutionary stage, powered by hot, massive stars (O8.5V-O8V). The H2 and PAH emission are highly correlated, with both decreasing as a function of eYSC age, indicating that PDR morphology evolves along the cluster emergence process. Using multiple independent line diagnostics, we find that radiative stellar feedback (i.e., photoionization) is dominant, with little contributions from supernovae-driven shocks. This highlights the importance of pre-supernovae feedback in regulating star formation, in line with recent literature.
For the first time, we can reveal the resolved spectral properties of eYSCs, their PDR, and single out stellar feedback mechanisms outside of the Local Group, showcasing the potential of the JWST/MOS mode for nearby galaxies.