



The proposed PhD project falls within the context of the scientific exploitation of data from the JWST, Herschel, and Planck space missions, as well as the preparation for the future PRIMA mission. It aims to improve our understanding of the complex growth of structures leading to star formation in the cold interstellar medium of galaxies.
Two fundamental, highly debated issues concern: 1) what regulates the star formation efficiency (SFE) in giant molecular clouds (GMCs), and 2) what sets the distribution of stellar masses at birth or « initial mass function » (IMF). To make decisive progress on these issues, the project will make use of:
1) High-angular resolution observations with the MIRI instrument on the JWST space telescope, as well as complementary submillimeter observations with ALMA, Herschel, and the ArTéMiS submillimeter camera (to be upgraded soon into the submm polarimetric imager POLARYS), developed at CEA/Irfu;
2) Millimeter-wave follow-up observations of gas kinematics via molecular lines using the IRAM, APEX, and ALMA radio telescopes, on the one hand, and of the magnetic field via polarized dust emission by combining data from the Planck satellite with those from the new NIKA2-Pol polarimeter on the IRAM 30m telescope, on the other hand;
3) Comparisons with state-of-the-art 3D simulations (non-ideal MHD) of filaments forming on the surface of interstellar bubbles.
Ultimately, the ambition of the project is to achieve a more complete, observationally-based understanding of galactic star formation, from the processes of formation and evolution of large filamentary structures within which stars form in molecular clouds, to the formation of individual solar systems at the smallest scales.

