Improvement of merging processes in N-body simulations in circumstellar disks

In the late stage of terrestrial planet formation planetary embryos grow to planets due to collisions with other planetary embryos or planetesimals. These collisions have to be accretive for growth. Due to perturbations by a secondary star, relative velocities among the disk objects may be increased and hence collisions may become destructive. In this work, we implemented the analytic model for predicting the collision outcomes by Leinhardt & Stewart (2012) (LS12) in our GPU parallelized N-body code GANBISS. We carried out N-body simulations of a fully interacting planetary embryo-planetesimal disk consisting of 25 embryos and 1000 planetesimals in S-type motion in various binary star configurations and comparing the LS12 collision outcomes with the perfect merging approach and subsequent analysis of the collisions in a post-processing step. Overall more destructive collisions occur in the simulations when applying the LS12 model. Additionally, we find in some binary configurations a significant mass loss due to destructive collisions, when applying the LS12 model.