| date: |
2010 June 16 (Wed) 16:00-
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| room: |
Kobe University, Science and Technology Research Building #4-809
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| speaker: |
Koji Wada (Chitech)
|
| title: |
To be, or not to be: that is the question of dust aggregates
|
| abstract: |
Impact processes in our Solar system play a crucial role in formation
and evolution of the planets. In particular, formation process of
planetesimals through collisions of dust aggregates still remains
unclear. We perform numerical simulations of aggregate collisions to
examine the evolution of dust aggregates in protoplanetary disks. As a
result, we have found that aggregates are not compressed well by their
mutual collisions and the fractal dimension of the compressed aggregates
is at most ~ 2.5. The aggregates composed of ice particles are feasible
to grow even if the impact velocities are as high as a few tens of m/s.
These numerical results suggest that very fluffy planetesimals can be
formed in protoplanetary disks by direct collisional growth of dust.
There are still many problems remaining, such as the feasibility of
collisional growth of silicate aggregates. We believe that these
problems are resolved through our collision simulations and the growth
of dust aggregates are fully understood in the future.
|
