Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2K084


Dullemond, Cornelis Petrus (Heidelberg University, Institute for Theoretical Astrophysics, Albert-Ueberle-Strasse 2, 69120 Heidelberg, Germany)
Johansen, Anders (Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, 22100 Lund, Sweden)

We show that the impact debris from a high-speed collision between two planetesimals during the first few million years would sweep up the nebular gas as a snow plow, leading to deceleration and compression of the debris into a thin shell. This shell breaks up into dense bullets through the Rayleigh-Taylor instability. As a result of the compression by the gas, these bullets will have super-Roche densities and thus will gravitationally collapse to form new planetesimals. Chondrules that may have formed from impact melting would thus rapidly be reaccreted into planetesimals. These dense environments are ideal for forming compound chondrules. The hydrodynamic interaction with the nebular gas could lead to mixing between the newly formed chondrules and surviving pre-impact material. Volatiles can be exchanged between these components in the dense bullets, allowing for chemical complementarity. We believe that this scenario may have some advantages over earlier impact scenarios for chondrule formation.

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