Contribution Invited Talk
PAHs and Fullerenes in space
There is an increasing observational evidence that a non-negligible fraction of the cosmic carbon is locked into macromolecules, mainly Polycyclic Aromatic Hydrocarbons (PAHs) and fullerene C60. However, very little is known about the formation pathways and physical processing of such structures under the extreme conditions commonly found in space.
In the first part of this talk I will discuss the modifications induced on interstellar PAHs via interactions with energetic ions, electrons and photons, highlighting the physics underpinning these phenomena and their implications on the observable characteristics of the molecules.
In the second part of the talk I will detail the model that we have recently proposed for the formation of C60 from carbonaceous nanoparticles in interstellar and circumstellar environments, where the very low density precludes the known vaporisation and combustion synthesis routes. Finally, I will present some current challenges and discuss the steps to be taken to advance our knowledge in this field, emphasising the importance of the interplay between theory, experiments and observations.