Abstract
Based in chemodynamical models for galaxy evolution, we studied the formation of PAH lines at high redshifts. The model considers carbon and silicon grains, and also PAH molecules. It distinguishes diffuse ISM the molecular clouds associated to star forming regions. The PAH lines provide a good signature of the evolutionary stage of galaxies, star formation rate, in addition to allowing the assessment the relative importance for of AGN and stellar emission on the output of the galaxy. In particular, the line ratio 11.3/7.7 μ m is a good marker of the age of high redshift galaxies. We expected that our calculations provide some benchmarks both for future observations both with ground and satellite instruments. The ages derived in this way for high redshift objects could be used to test dark energy models. In addition to the cosmological applications, the observations of the PAH features could be used to check the charge state of PAHs. Apparently, anions and neutrals are favored over cations.
