Oral Presentation

Infall Onto Protoplanetary Disks Across Evolutionary Stages

Author(s): León-Alexander Hühn (Heidelberg University, Peking University)

Presenter: León-Alexander Hühn (Peking University)

The classical method of treating protoplanetary disks and planet formation in an isolated environment during the Class II evolutionary stage is increasingly being challenged, especially by recent observational findings.
On the one hand, substructures in pre-Class II disks like HL Tau and some targets of the eDISK program, and potential issues with the solid mass budget of Class II disks, have highlighted the importance of considering the onset of planet formation with special care for the younger Class 0/I disks. For this reason, it is imperative to understand what drives the evolution of these young disks, and how the early stages of planet formation operate, linking the prestellar core conditions to the disk's physical conditions.
On the other hand, ubiquitous occurrences of the inflow of material in the form of streamers onto older disks in the Taurus and other star forming regions are being discovered. Such interactions have considerable implications for the formation and evolution of substructures in more evolved protoplanetary disks, because they supply fresh material and impact disk dynamics.

In this talk, I highlight the various ways infall can become important for planet formation across all the different evolutionary stages of protoplanetary disks, from young to old. First, I present a study of the dynamical evolution of young Class 0/I disks from star formation simulations, and show how planetesimals might form in these early disks, which are heavily dominated by infall. The formation of these planetesimals is crucial to understand the initial conditions of planet formation commencing at the later stages. After that, I explore how streamers can arise naturally in hydrodynamics simulations considering different environmental conditions, showing that turbulent Bondi-Hoyle-Lyttleton accretion processes can cause a variety of morphologies, like spiral patterns or large-scale streamers. Especially at the later disk stages, the perturbations might have considerable impact on the now lighter disk, opening the possibility for a new pathway of the formation of second generation planets.