Collisional Growth and Fragmentation of Dust Aggregates with Low Mass Ratios. I. Critical Collision Velocity for Water Ice
Collisional Growth and Fragmentation of Dust Aggregates with Low Mass Ratios. I. Critical Collision Velocity for Water Ice
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DOI：
10.3847/1538-4357/abf6cf
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发表时间：
2021-07-01
影响因子：
4.9
通讯作者：
Wada, Koji
中科院分区：
文献类型：
--
作者：
Hasegawa, Yukihiko;Suzuki, Takeru K.;Wada, Koji
通过对亚微米大小的冰尘单体进行n体模拟，研究了尘埃聚集体碰撞粘附和破碎的基本过程。在质量比为1-64的大范围内，研究了两种碰撞尘埃聚集体的碰撞生长条件。我们发现，在质量比为2-30、撞击速度约为30-170 m s（-1）的情况下，较大的尘埃聚集体向较小的尘埃聚集体的质量传递是主要的碰撞过程。结果，对于这种不等质量的碰撞，最大物体破碎的临界速度v （fra）大大降低；质量比为3的碰撞的V （fra）约为等质量碰撞的一半。在典型的原行星盘（PPDs）条件下，由于径向漂移速度的差异，高质量比的尘埃聚集体之间的碰撞速度通常更高。因此，等质量碰撞的简化v （fra）会延迟PPDs内部区域尘埃颗粒的生长。
We investigated fundamental processes of collisional sticking and fragmentation of dust aggregates by carrying out N-body simulations of submicron-sized icy dust monomers. We examined the conditions for collisional growth of two colliding dust aggregates in a wide range of the mass ratio 1-64. We found that the mass transfer from a larger dust aggregate to a smaller one is a dominant process in collisions with a mass ratio of 2-30 and an impact velocity of approximate to 30-170 m s(-1). As a result, the critical velocity, v (fra), for fragmentation of the largest body is considerably reduced for such unequal-mass collisions; v (fra) of collisions with a mass ratio of 3 is about half of that obtained from equal-mass collisions. The impact velocity is generally higher for collisions between dust aggregates with higher mass ratios because of the difference between the radial drift velocities in the typical condition of protoplanetary disks (PPDs). Therefore, the reduced v (fra) for unequal-mass collisions would delay growth of dust grains in the inner region of PPDs.