Abstract
In order to understand the chemical and thermodynamical state of the interstellar medium (ISM) in the early stage of galaxy evolution, dust formation needs to be considered. Even in metal poor galaxies, dust grains can drastically accelerate the formation rate of molecular hydrogen (H[2]). Hydrogen molecules emit vibrational-rotational lines, thus cooling the gas. Consequently, the abundance of the molecules affects the spectrum and the cooling rate of a galaxy.
