The next SFB-colloquium will be on October 28 at 2 pm in the Lecture Hall III of the Physics Institutes in Cologne.
Maria Jose Maureira from the Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching will talk about “Thick, Massive and Hot: Protostellar Disks and the Onset of Planet Formation“.
Recent observations have overturned the long-standing view that star and planet formation occur in separate stages, showing instead that planets likely begin forming while the protostar is still accreting (Class 0/I). Yet most of our knowledge of planet-forming disks comes from later-stage disks (Class II), leaving the youngest protostellar disks largely unexplored. Characterizing the physical conditions of accreting protostellar disks is crucial for understanding stellar mass assembly and the onset of planet formation. 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. The results highlight the importance of building a new observation-based model for the youngest disks that can be used to test theories of early star and planet formation.