1. Image: ISAS/JAXA Christopher Stark University of Maryland NASA Goddard Space Flight Center Collisional Grooming: Including Collisions in (Prohibitively Large) N-body Simulations

2. Fomalhaut Kalas et al. 2005 Greaves et al. 1998  Eri Schneider et al. 2009 HR 4796A

3. Kalas et al. 2008

6. Fomalhaut Kalas et al. 2005 Greaves et al. 1998  Eri Schneider et al. 2009 HR 4796A

7. Velocity Dispersion in a Structured Debris Disk

8. PR + solar wind drag Stellar gravitational force Planetary gravitational forces Radiation pressure

9. N i = N i (t=0) N i (t=  t) = N i (t=0)e -  N i (t=2  t) = N i (t=  t)e -  N i (t=3  t) = N i (t=2  t)e -  i i i The Collisional Grooming Algorithm

10. Iterative Convergence of the Collisional Grooming Algorithm

11. Correctness of Solution to the Mass Flux Equation

12. Collision Rate in a Resonant Ring Structure

14. No Collisions More Collisions

15. N i = N i (t=0) N i (t=  t) = N i (t=0)e -  i Fragmentation

17. Fomalhaut Kalas et al. 2005 Greaves et al. 1998  Eri Schneider et al. 2009 HR 4796A

18. Distribution of KBOs

19. = 0.6  m

20. = 60  m

21. = 800  m

22. Disk-Total Grain Size Distribution

23. Summary Grain-grain collisions play an important role in determining debris disk morphology, even for disks with optical depths ~10 -7 Collisional grooming allows us to include gravitational resonant dynamics and grain-grain collisions simultaneously & self-consistently Algorithm runs post-integration & takes ~1 hour on a single processor