Abstract. The core excitations of the furan and carbon dioxide molecules have been studied using dispersed UV-visible fluorescence spectroscopy. Balmer-α (Balmer-β) emission was measured at the O 1s and C 1s (O 1s) excitations of furan, while emission due to an excited state of the neutral oxygen atom was measured at the O 1s excitations of CO₂. The excitation functions of the emission lines display both valence and Rydberg resonances, but the latter are more enhanced.