Tetsuo Yamamoto¹, Toshihiko Kadono², and Koji Wada³

¹Center for Planetary Science, Integrated Research Center of Kobe University, Minatojima, Chuo-ku, Kobe 650-0047, Japan
²School of Medicine, University of Occupational and Environmental Health, Yahatanishi-ku, Kitakyushu, Fukuoka 807-8555, Japan
³Planetary Exploration Research Center, Chiba Institute of Technology, Tsudanuma 2-17-1, Chiba 275-0016, Japan

N-body simulations of collisions of dust aggregates in protoplanetary disks performed so far have revealed that silicate aggregates suffer from catastrophic disruption if the collision velocities are higher than about 10 m s^-1, which is much lower than those expected in the disks. This is mainly due to the low surface energy of the quartz used in the simulations. We find a simple relation between the surface energy and melting temperature for various materials including those of astrophysical interest, and show that the surface energy of the quartz used in the previous simulations is much lower than the present estimate. This result may provide a way out of the difficulty of growing silicate dust inside the snowline in disks. We show that silicate dust can evade catastrophic disruption and grow even at high-velocity collisions expected in the disks if one takes the present estimate of the surface energy into account.

Reference
Yamamoto T, Kadono T and Wada K (2014) An examination of collisional growth of silicate dust in protoplanetary disks. The Astrophysical Journal – Letters 784:L36.
[doi:10.1088/2041-8205/783/2/L36]

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