The feasible photoinduced growth of polycyclic aromatic hydrocarbons from cosmic benzene ice

The reactive phenyl radical, electronically excited benzene monomer and dimer, their radical cations and low-atomic neutral hydrocarbons may be born in situ via the photodissociation/photoionization of a gaseous benzene monomer/dimer photo-desorbed from cosmic ice as well as via the subsequent dissociative recombination of the arisen benzene cations. The above-mentioned species can be the sources for the assembly into large polycyclic aromatic hydrocarbons, which can occur at very low temperatures and pressures in the interstellar medium.