Collisional Growth Conditions for Dust Aggregates
Collisional Growth Conditions for Dust Aggregates
复制标题
粉尘聚集体的碰撞生长条件
DOI：
10.1088/0004-637x/702/2/1490
复制
发表时间：
2009
影响因子：
4.9
通讯作者：
T. Yamamoto
中科院分区：
文献类型：
--
作者：
K. Wada;H. Tanaka;T. Suyama;H. Kimura;T. Yamamoto
尘埃聚集体之间的碰撞是理解行星体形成的关键，因为碰撞不可避免地发生在原行星盘中。为了弄清尘埃聚集体是否可以通过相互碰撞以相对较高的速度生长，我们对弹道粒子-星团聚集(BPCA)下形成的冰状等质量星团之间的碰撞以及弹道星团-星团聚集的碰撞进行了4000多次三维数值模拟，包括不同碰撞参数值的偏置碰撞。由于我们的BPCA星系团具有3的分维和相对紧凑的结构，它们的结果使我们能够确定压缩聚集体在原行星盘中碰撞时的增长和破裂的标准。结果表明，无论冰尘集合体的初始结构和碰撞参数如何，在速度高达50ms−1的碰撞中，冰尘集合体都能生长。我们还发现，抛射物的质量相对于碰撞聚集体的总质量随着聚集体大小的增加而减小。这些结果证明了尘埃聚集体在原行星盘中以相对较高的速度相互碰撞而生长和生存的可行性。
Collisions between dust aggregates are the key to understand the formation of planetesimals because the collision inevitably takes place in protoplanetary disks. To clarify whether or not dust aggregates can grow through their mutual collisions at relatively high velocities, we carry out more than 4000 runs of three-dimensional numerical simulations of collisions between icy equal-mass clusters formed under ballistic particle–cluster aggregation (BPCA) as well as those of ballistic cluster–cluster aggregation, including offset collisions with various values of the impact parameter. Since our BPCA clusters have a fractal dimension of 3 and a relatively compact structure, their results enable us to determine the criteria for growth and disruption of compressed aggregates at their collisions in protoplanetary disks. The results show that ice dust aggregates are able to grow at collisions with velocities up to 50 ms− 1, in spite of their initial structures and impact parameters. We also find that the mass of ejecta relative to the total mass of colliding aggregates decreases with increasing the size of the aggregates. These results demonstrate the feasibility of growth and survival for dust aggregates through their mutual collisions with relatively high velocities in protoplanetary disks.