We have carried out a set of numerical simulations of the collisional evolutional of the main asteroid belt, based on some models of fragmentation and cratering events consistent with the available experimental results on the outcomes of high-velocity impacts. The asteroidal population has been divided into a sequence of discrete size bins, down from Ceres' diameter (about 1000 km) to arbitrarily small sizes; the bins have a constant logarithmic width, corresponding to a factor two in the mass of the bodies. A simple particles-in-a-box formula has been used to compute in every time step the number of collisions involving bodies belonging to any given pair of size bins. Then we have numerically integrated over a time of 4.5 billion years a set of first-order differential equations for the populations of the bins, considering the redistribution of the objects caused by collisions and including a sink term modeling the removal of small particles by non-gravitational effects (such as the Poynting-Robertson drag). The initial conditions were chosen to be consistent with a primordial asteroid population following two power-law size distributions, joined at a transition diameter of 100 km.
COLLISIONAL EVOLUTION OF THE ASTEROID SIZE DISTRIBUTION: A NUMERICAL SIMULATION
PAOLICCHI, PAOLO
1993-01-01
Abstract
We have carried out a set of numerical simulations of the collisional evolutional of the main asteroid belt, based on some models of fragmentation and cratering events consistent with the available experimental results on the outcomes of high-velocity impacts. The asteroidal population has been divided into a sequence of discrete size bins, down from Ceres' diameter (about 1000 km) to arbitrarily small sizes; the bins have a constant logarithmic width, corresponding to a factor two in the mass of the bodies. A simple particles-in-a-box formula has been used to compute in every time step the number of collisions involving bodies belonging to any given pair of size bins. Then we have numerically integrated over a time of 4.5 billion years a set of first-order differential equations for the populations of the bins, considering the redistribution of the objects caused by collisions and including a sink term modeling the removal of small particles by non-gravitational effects (such as the Poynting-Robertson drag). The initial conditions were chosen to be consistent with a primordial asteroid population following two power-law size distributions, joined at a transition diameter of 100 km.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
