Zhihao Fu   (China)

 zhfu @ mpia.de

Numerical Simulations on Collapse of Pebble Clouds

The earliest planetary embryos likely formed through turbulent processes within the solar nebula, which aggregated pebbles into self-gravitating clumps that ultimately collapsed into planetesimals approximately 10 to 100 km in diameter. Despite advances in dust accretion, disc instabilities, fluid instabilities, and pebble cloud collapse, modelling these stages remains puzzled by inconsistent assumptions.

We shall develop Lagrangian simulations to trace the collapse of pebble clouds into solid-density bodies. Implicit time integration via SPH or other meshless methods (such as GIZMO) will incorporate self-gravity, elasticity, and porosity evolution models. This approach will eliminate time-step constraints imposed by solid-phase sound velocity settings, enabling long-duration free-fall runs.

Establishing initial conditions based on research findings concerning turbulent-regulated pebble size, opacity, and dendritic gravity cloud characteristics, we shall predict the initial mass function, morphology, spin state, multiplicity (including binary systems), and internal structure of protoplanetary embryos across various distance layers within the Solar System. These predictions will ultimately be validated against asteroids, comets, and Kuiper Belt objects.

 

Supervisor:    Hubert Klahr   (MPIA)