Protostars and Planets VI, Heidelberg, July 15-20, 2013
Static compression of porous dust aggregates
Kataoka, Akimasa (NAOJ/SOKENDAI)
Tanaka, Hidekazu (Hokkaido University)
Okuzumi, Satoshi (Tokyo Tech)
Wada, Koji (Chiba Institute of Technology)
To understand the structure evolution of dust aggregates is a key in the planetesimal formation. Dust grains become fluffy by coagulation in protoplanetary disks. However, once they become fluffy, they are not sufficiently compressed by collisional compression to form compact planetesimals (Okuzumi et al. 2012, ApJ, 752, 106). Thus, some other compression mechanisms are required to form planetesimals.
We investigate the static compression of highly porous aggregates. First, we derive the compressive strength by numerical N-body simulations (Kataoka et al. 2013, A&A, 554, 4). Then, we apply the strength to protoplanetary disks, supposing that the highly porous aggregates can be quiasi-statically compressed by ram pressure of the disk gas and the self gravity. As a result, we find the pathway of the dust structure evolution from dust grains via fluffy aggregates to compact planetesimals. Moreover, we find that the fluffy aggregates overcome the barriers in planetesimal formation, which are radial drift, fragmentation, and bouncing barriers.
(The paper is now available on arXiv: http://arxiv.org/abs/1307.7984 )
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