Fragmentation kinetics of fuzzy aggregates: application to planetary rings

• Grant number: 06/01941-0
• Support Opportunities: Scholarships abroad - New Frontiers
• Effective date (Start): August 01, 2007
• Effective date (End): July 31, 2008
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Solar System Astronomy
• Principal Investigator: Ernesto Vieira Neto
• Grantee: Ernesto Vieira Neto
• Host Investigator: Frank Spahn
• Host Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil
• Research place: University of Potsdam, Germany

Abstract

Fragmentation dynamics of fuzzy aggregates upon collision is studied in the contextof the kinetic description of planetary rings. We elaborate a fragmentationmodel which gives the distribution function for the velocities and masses of debrisproduced in collisions. These quantities are expressed in terms of the kinetic energyof colliding particles, the material properties of the particles and their size. Weapply two approaches, a simplified one, where the model of an effective mediumwith empirical parameters is used and a more advanced approach where the empiricalparameters are estimated from the structural properties of fuzzy aggregates hold together by adhesion. Based on the fragmentation model we derive a kinetickernel for the Boltzmann-Smoluchowski equation which describes fragmentatingcollisions and analyze its impact on the stationary size distribution of particles inplanetary rings. (AU)