Charge and energy sharing in the fragmentation of astrophysically relevant carbon clusters

Abstract

The breakup of a molecule following a fast collision with an atom in gas phase can be understood as resulting from two steps. In the first step, the atom transfers energy to the molecule, which is thus electronically and vibrationally excited. In the second step, the molecule decays leading to different fragments, while the initial charge, energy, and angular momentum are conserved. Here, we demonstrate that, by maximizing the entropy of the system under these conservation laws, it is possible to reproduce the fragmentation yields resulting from collision experiments. In particular, our model is applied to investigate fragmentation of excited neutral and singly charged carbon clusters and mono-hydrogenated carbon clusters. These species are commonly exposed to energetic ionizing radiation in the interstellar medium, so understanding the key aspects of their fragmentation, in particular the way energy and charge are shared in the process, can be relevant to get a deeper insight on the evolution of carbonaceous species in the universe.