Fragmentation model dependence of collision cascades

Hiroshi Kobayashi, Hidekazu Tanaka

Research output: Contribution to journalArticlepeer-review

81 Citations (Scopus)


Mass depletion of bodies through successive collisional disruptions (i.e., collision cascade) is one of the most important processes in the studies of the asteroids belt, the Edgeworth-Kuiper belt, debris disks, and planetary formation. The collisional disruption is divided into two types, i.e., catastrophic disruption and cratering. Although some studies of the collision cascades neglected the effect of cratering, it is unclear which type of disruption makes a dominant contribution to the collision cascades. In the present study, we construct a simple outcome model describing both catastrophic disruption and cratering, which has some parameters characterizing the total ejecta mass, the mass of the largest fragment, and the power-law exponent of the size distribution of fragments. Using this simple outcome model with parameters, we examine the model dependence of the mass depletion time in collision cascades for neglect of coalescence of colliding bodies due to high collisional velocities. We find the cratering collisions are much more effective in collision cascades than collisions with catastrophic disruption in a wide region of the model parameters. It is also found that the mass depletion time in collision cascades is mainly governed by the total ejecta mass and almost insensitive to the mass of the largest fragment and the power-law exponent of fragments for a realistic parameter region. The total ejecta mass is usually determined by the ratio of the impact energy divided by the target mass (i.e. Q-value) to its threshold value QD{black star} for catastrophic disruption, as well as in our simple model. We derive a mass depletion time in collision cascades, which is determined by QD{black star} of the high-mass end of collision cascades. The mass depletion time derived with our model would be applicable to debris disks and planetary formation.

Original languageEnglish
Pages (from-to)735-746
Number of pages12
Issue number2
Publication statusPublished - 2010 Apr
Externally publishedYes


  • Asteroids, Dynamics
  • Collisional physics
  • Planetary dynamics
  • Planetary formation

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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