Formation of planetesimals via the streaming instability - numerical simulations -
Final Report Abstract
Planets are objects orbiting one or more central stars, like the eight planets in our solar system orbiting the sun. By now we also know more than 5000 extrasolar planets, i.e. planets orbiting other stars but the sun. Despite of our improved knowlege within the last decades on planets and planetary systems, we still don’t fully understand how planets are formed. The general scenario is that planets are formed out of the protoplanetary disc surrounding newborn stars and hence their formation is closely linked to the formation of stars themselves. In the protoplanetary discs surrounding young stars, micron-sized dust grains grow over more than ten orders of magnitude in size until they form planets. For this process, instabilities in the protoplanetary disc play an important role as the smooth dust distribution has to be disturbed to allow the concentration of dust into clumps which eventually develop to planetesimal and further to planets. Within this project we confirmed that the streaming instability and the vertical shear instability play an important role to provide such overdense structures. In particular, we could show with unprecedented numerical simulations that the interplay of both instabilities lead to very dense dust structures in protoplanetary disc which are likely to form planetesimals.
Publications
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PhD thesis "Turbulence and planetesimal formation induced by the streaming instability”, Universität Hamburg, August 2020
Urs Schäfer
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The coexistence of the streaming instability and the vertical shear instability in protoplanetary disks. Astronomy & Astrophysics, 635, A190.
Schäfer, Urs; Johansen, Anders & Banerjee, Robi
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The coexistence of the streaming instability and the vertical shear instability in protoplanetary disks. Astronomy & Astrophysics, 666 (2022, 10), A98.
Schäfer, Urs & Johansen, Anders
