Description du projet
Une nouvelle recherche jette un éclairage sur la formation des étoiles massives
Les disques circumstellaires constituent un ingrédient essentiel lors de la formation d’étoiles de faible masse comme notre Soleil. La formation d’étoiles plus massives, d’une masse solaire environ huit fois plus importante, ne suit pas nécessairement ce même processus. Le projet Magik Star, financé par l’UE, s’est fixé pour objectif d’étudier plus en profondeur ce problème qui occupe les astrophysiciens depuis longtemps. En s’appuyant sur des recherches récentes qui sont parvenues à corréler les flux entrant en collision et la formation d’étoiles de masse élevée, les chercheurs combineront les résultats de ces recherches avec des études portant sur le champ magnétique, qui se sont également révélées importantes dans le processus de formation des étoiles. Les travaux numériques seront complétés par des observations expérimentales au radiotélescope ALMA. Les résultats fourniront des informations plus détaillées sur la formation des étoiles massives, informations qui se sont jusqu’à présent montrées rares, car ces étoiles sont rares elles-aussi.
Objectif
Star formation is a fundamental process in astrophysics, which has been studied for decades. As of now, most of our knowledge is concentrated on the formation of stars of a few solar masses. If galaxies' total stellar mass is dominated by low-mass stars, their energy budget is exclusively controlled by the enormous luminosity and powerful feedback of massive stars (M > 8 Msun). Despite their importance, the mechanisms leading to the formation of high-mass stars remain a mystery in many aspects. From the theoretical point of view, low-mass star formation models are not directly transposable as they do not provide accretion rates in line with what is necessary for high-mass star formation. From the observational point of view, until the recent rise of large interferometers, little was known about the formation of massive stars due to their scarcity, and remoteness. Through my work with interferometers, I have proved that very dynamical processes (colliding flows) are at play in high-mass star-forming regions (HMSFR). On the other hand, recent studies have shown that magnetic fields are a key factor in the regulation of star-formation. I am convinced that the dynamical features observed in HMSFR coupled with the action of the magnetic fields could explain for the formation of high-mass stars. For this two-year project, I plan on studying the coupling of gas dynamics with magnetic fields. For this purpose, I present an innovative project that will study this coupling simultaneously from observational and numerical inquiries. I will use today's best instrument in radio-astronomy, ALMA, to trace both the kinematics of gas and the magnetic field morphology. This observational part relies on data that I have already acquired. For the numerical part, I will participate in the development of dedicated magneto-hydro-dynamical simulations together with P. Hennebelle to understand the physical processes that underlie the observational features.
Champ scientifique
Programme(s)
Régime de financement
MSCA-IF-EF-ST - Standard EFCoordinateur
75015 PARIS 15
France