2025-05-28 –, Main Conference Room
Significant progress has been made in characterizing the star formation (SF) timeline in Giant Molecular Clouds (GMCs), taking advantage of high-resolution multi-wavelength observations and robust statistical methods that contrast tracers of molecular gas (e.g., CO) with tracers of SF (e.g., Ha). However, our understanding of the early feedback phase, when stars are still embedded in gas and dust, has been so far limited by the lack of high-resolution infrared data. This is now possible with the spatial resolution and sensitivity provided by JWST.
Using 30 galaxies from the PHANGS-JWST survey, we aim to derive new constraints on the physical mechanisms associated with early feedback and the emergence of clusters from their birth clouds. We derive the total duration of the dust-emitted 21um emission and find that it correlates with the averaged mass and velocity dispersion of the GMCs, with evidence for secondary dependencies on galactic morphological type and metallicity. Regardless of these variations, we find that the deeply embedded phase of the SF is short in all galaxies in our sample, with a maximum of only 5 Myr in the most metal-rich environments.
Our results indicate a rapid - sometimes absent - transition from the embedded to the exposed phase of SF in a sample of nearby star-forming galaxies covering a wide range of physical conditions. I will discuss what physical processes could be responsible for these short timescales, and how additional spectroscopic information can help to disentangle different scenarios.
