Mixed aliphatic and aromatic composition of evaporating very small grains in NGC 7023 revealed by the 3.4/3.3 $\mu$m ratio

P. Pilleri, C. Joblin, F. Boulanger +1

In photon-dominated regions (PDRs), UV photons from nearby stars lead to the evaporation of very small grains (VSGs) and the production of gas-phase polycyclic aromatic hydrocarbon…