Astronomers can study the environment of astronomical objects by observing spectral lines from molecules near those objects. This article considers a class of molecules called Polycyclic Aromatic Hydrocarbons (PAHs) near type-1 active galactic nuclei (AGNs). By studying spectral lines associated with PAHs near type-1 AGNs, astronomers can better understand properties of type-1 AGNs and their surroundings.

http://www.raa-journal.org/raa/index.php/raa/article/view/1878