Collisional rates and impact velocities of short-period comets with interplanetary particles

Distributions of collision velocities between short-period comets and particles in the asteroid belt are computed for a sample of 159 objects. For every comet, the mean intrinsic collision probability and the mean collision velocity were obtained. The mean values for the complete sample are < P-i> = 1.51 x 10(-18) km(2) year(-1) and <nu(col)> = 10.86 km s(-1), and the results for the observable and lost comet samples are: < P-i> = 1.45 x 10(-18) km(-2) year(-1), <nu(col)> = 10.45 km s(-1), and < P-i> = 1.88 x 10(-18) km(-2) year(-1), <nu(col)> = 12.78 km s(-1), respectively. The results obtained show that the collisions occur over a wide and asymmetric range of velocities, and the distributions for individual objects are completely different from each other and often contain fine structure, irregularities and spikes (C) 2000 Elsevier Science Ltd. All rights reserved.