We present the unique capabilities of SOFIA to map the sizes of the Polycyclic Aromatic Hydrocarbons (PAHs) using the FORCAST and FLITECAM instruments. We create maps of the 11.2/3.3 µm ratio to probe the morphology of the PAH size distribution and the 8.0/11.2 µm ratio to probe the PAH ionization. The PAH sizes are obtained by making use of an emission model and of vibrational spectra from the NASA Ames PAH database. We study the photochemical evolution of the PAHs by comparing the PAH size map with among others the molecular Hydrogen emission (2.12 µm) and emission from evaporating Very Small Grains (eVSG).
Mapping PAH sizes in NGC 7023 with SOFIA