Following the gas from dense core to protostellar disk
Mardi 08/10/2019, 10:00-11:00
Bat 713, salle de séminaires Galilée , CEA Saclay, Orme des Merisiers
A detailed understanding of star-formation is important to establish the "micro-physics" involved in the galactic star-formation relations, and also to determine the initial condition for proto-planetary disks. One of the important steps in the star-formation process is the accumulation of material from the molecular cloud with supersonic turbulence into the dense cores, which have subsonic turbulence. The first direct observation of the transition between supersonic and subsonic turbulence in a nearby cloud provided the first direct constraints on this dissipation process. On the other hand, recent observations have shown that large protoplanetary disks in the early stages are relatively rare, and for those that are large, there is compelling evidence for asymmetries related to gravitational instabilities. However, little is known of the connection between the disks and the parental dense core.
In this talk, I will present some of our latest efforts on studying the dense core and molecular cloud connection, thanks to a large program at the Green Bank Telescope (~250hrs, PIs: Jaime Pineda and Rachel Friesen). This survey allows us to more accurately determine the dense core properties in a systematic fashion and across several clouds. Also, I will present interferometric observations of dense cores that will provide new insight into the core formation and the material transport down to the scales relevant for disk formation.
Local contact: A. Maury
Organization: M. Galametz