Shattering of dust grains in the interstellar medium is a viable mechanism of small grain production in galaxies. We examine the robustness or uncertainty in the theoretical predictions of shattering. We identify P1 (the critical pressure above which the deformation destroys the original lattice structures) as the most important quantity in determining the timescale of small grain production, and confirm that the same P1/t (t is the duration of shattering) gives the same grain size distribution [n(a), where a is the grain radius] after shattering within a factor of 3. The uncertainty in the fraction of shocked material that is eventually ejected as fragments causes uncertainties in n(a) by a factor of 1.3 and 1.6 for silicate and carbonaceous dust, respectively. The size distribution of shattered fragments have minor effects as long as αf≤ 3.5 (the size distribution of shattered fragments ∝ a-αf), since the slope of grain size distribution n(a) continuously changes by shattering and becomes consistent with n(a) ∝ a-3.5. The grain velocities as a function of grain radius can have an imprint in the grain size distribution especially for carbonaceous dust. We also show that the formulation of shattering can be simplified without losing sufficient precision.
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机译：星际介质中尘埃颗粒的破碎是星系中小颗粒产生的可行机制。我们研究了破碎的理论预测中的鲁棒性或不确定性。我们确定P 1 （高于该临界压力，变形会破坏原始晶格结构）是确定小晶粒生产时间尺度的最重要量，并确认相同的P 1 < / SUB> / t（t是粉碎的持续时间）在粉碎后以3为单位给出了相同的晶粒尺寸分布[n（a），其中a是晶粒半径]。最终以碎片形式喷出，分别导致硅酸盐和碳尘的n（a）不确定性分别为1.3和1.6。只要α f ≤3.5（破碎碎片的大小分布∝ a -α f ），破碎碎片的大小分布都会产生较小的影响。 ，由于晶粒尺寸分布的斜率n（a）随破碎而连续变化，并与n（a）∝ a -3.5 一致。随颗粒半径变化的颗粒速度会在颗粒尺寸分布中产生影响，特别是对于含碳粉尘。我们还表明，可以简化粉碎过程，而不会损失足够的精度。
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