{
  "id": "1909.07001",
  "version": "v1",
  "published": "2019-09-16T05:59:57.000Z",
  "updated": "2019-09-16T05:59:57.000Z",
  "title": "Rotational disruption of dust grains by high-velocity gas-grain collisions",
  "authors": [
    "Thiem Hoang",
    "Hyeseung Lee"
  ],
  "comment": "9 pages, 4 figures; to be submitted; comments welcome",
  "categories": [
    "astro-ph.GA",
    "astro-ph.EP",
    "astro-ph.HE",
    "physics.space-ph"
  ],
  "abstract": "Dust grains moving at hypersonic velocities of $v_{d}\\gtrsim 100~\\rm km~s^{-1}$ through an ambient gas are known to be destroyed efficiently by nonthermal sputtering. Yet, previous studies of nonthermal sputtering disregarded the fact that the grain can be spun-up to suprathermal rotation by stochastic gas-grain collisions. In this paper, we show that such a suprathermal rotation results in the disruption of the small grain into molecules because the induced centrifugal stress can exceed the maximum tensile strength of grain material, $S_{\\rm max}$. We term this mechanism {\\it rotational disruption}. We find that rotational disruption is more efficient than nonthermal sputtering in destroying small dust grains of nonideal internal structures moving with velocities of $v_{d}>100 ~\\rm km~s^{-1}$. The ratio of rotational disruption to sputtering time is $\\tau_{\\rm disr}/\\tau_{sp}\\sim 0.2(S_{\\rm max}/10^{9}\\rm erg~cm^{-3})(Y_{sp}/0.1)(a/0.01\\mu m)^{3}(300~\\rm km~s^{-1}/v_{d})^{2}$ where $a$ is the radius of spherical grains, and $Y_{sp}$ is the sputtering yield. We discuss the implication of this mechanism for the destruction of hypersonic grains accelerated by radiation pressure as well as grains in fast shocks. Our results suggest that the destruction of dust grains in fast shocks of supernova remnants is more efficient than previously predicted by sputtering, which seems to be supported by the higher fraction of dust destruction observed in fast shocks of core-collapse supernovae.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-09-16T05:59:57.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "rotational disruption",
      "high-velocity gas-grain collisions",
      "fast shocks",
      "nonthermal sputtering",
      "stochastic gas-grain collisions"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}