Gas phase Elemental abundances in Molecular cloudS (GEMS)

Abstract

The gaseous H₂S abundance is well reproduced, assuming undepleted sulphur abundance and chemical desorption as the main source of H₂S. The behavior of the observed H₂S abundance suggests a changing desorption efficiency, which would probe the snowline in these cold cores. Our model, however, highly overestimates the observed gas-phase CS abundance. Given the uncertainty in the sulphur chemistry, we can only conclude that our data are consistent with a cosmic elemental S abundance with an uncertainty of a factor of 10.