Probing the Dissociation of Interstellar Polycyclic Aromatic Hydrocarbons

The presence of interstellar polycyclic aromatic hydrocarbons (PAHs) is inferred from their characteristic mid-infrared (IR) emission bands that are observed towards a large number of galactic and extragalactic sources. It has been derived that PAHs constitute up to 15% of the total cosmic carbon budget and thus play an important role in cosmochemical cycle of matter. Energetic processing of interstellar PAHs occurs in photon dominated regions and may result in ionization and/or dissociation of the aromatic species. Observational and laboratory data suggest that dissociation of large interstellar polyaromatics eventually leads to fullerene formation. Our group characterizes PAH dissociation processes by applying state-of-the-art experimental physicochemical techniques and combining the results with quantum chemical computations. Using this approach, we obtain insight into the dissociation mechanisms at the molecular level of detail. In this talk I will review our recent results and will emphasize the challenges that lie ahead of us.