Seminario DAS: The Secret Lives of Protostellar Disks: physical properties and dynamics during the earliest stages of star and planet formation

Speaker: María José Maureira
Affiliation: Max Planck Institute for Extraterrestrial Physics

Abstract: Characterizing the physical conditions of disks surrounding young protostars that are still actively accreting from their surroundings is crucial to understanding the mass assembly process of stars and the mechanisms for early planet formation. While the majority of theoretical investigations into the first steps to form planetesimals are still using physical properties akin to more evolved disks past the main accretion phase, it is expected that the physical properties in much younger disks will be different. In this talk, I will present ALMA observations with a resolution of 6 au towards young protostellar disks, with various morphologies and multiplicities. Using a multi-wavelength approach, we find that these disks are very optically thick, even at 3 mm. These high optical depths can help hiding the presence of early ’gaps’ related to the planet formation process, and also push the disk masses beyond the threshold for gravitational instability. The observations are also questioning the common assumption that star irradiation alone is the main mechanism controlling the disk temperature. Instead, the observed temperatures suggest that some young disks are ‘active’, thus also heated due to accretion and shocks. Finally, I will also discuss the first constraint of orbital parameters for a nascent binary system, derived from a unique set of ALMA and JVLA observations of the gas kinematics and stellar motions spanning ~ 30 years.