Astro Seminar
Unveiling emerging young star cluster properties in the JWST era: the FEAST project
Speaker: Helena Faustino Vieira (Stockholm)
Date: Wednesday 3 June 2026
Time: 14:00
Venue: N3.28
Once massive stars form, stellar feedback begins altering the structural, chemical and energetic properties of the interstellar medium, significantly affecting the efficiency of any subsequent star formation. This has important ramifications for planet formation and galactic evolution. JWST is perfectly placed to pierce through the dusty molecular clouds to reveal the young star clusters (YSCs) which are still in the process of emerging from their birthplace, and thus actively driving stellar feedback. I will present a census of thousands of YSCs (<10Myr) across a sample of nearby galaxies (M51, M83, NGC628, NGC4449, and NGC4485/4490), identified at 4–8 parsec resolution with HST and JWST, as part of the FEAST (Feedback in Emerging extrAgalactic Star clusTers) project. We resolve the stellar populations of the interacting pair NGC4485/4490, and recover the star formation history of these low-mass systems, highlighting the role mergers play in star formation. From the extensive YSC catalogue, we establish an emergence evolutionary sequence as YSCs transition from embedded to fully exposed (optically-bright). We find that natal clouds are cleared within ~4-7 Myr, and that this process is faster with increasing YSC mass. This points toward a scenario where pre-supernova feedback plays a key role in modifying and transforming the immediate surroundings, while supernovae set the final clearing. NIRSpec multiplex spectroscopy observations of NGC628 highlight the chemical richness of these star-forming regions, simultaneously probing the HII regions, photodissocation regions (PDRs) and stellar feedback. The spectroscopy paints a more accurate picture: as YSCs age, they become less embedded, with a fainter, less compact PDR. The YSCs do not show signatures of supernovae-driven shocks, corroborating that pre-supernova feedback is dominant, and supernovae take place in an already processed medium.