A search for solid H2S in dense clouds

Abstract

A search for solid H 2 S absorption features in a sample of six objects, consisting of three high-mass protostars (Mon R2/IRS-2, Mon R2/IRS-3 and W3/IRS-5), and three late-type field stars lying behind the Taurus dark cloud (Elias 16, Elias 13 and Elias 3), is presented. No evidence is found for absorption by solid H 2 S in any of these objects, and an absorbance value taken from the literature is used to place upper limits on the column densities of solid H 2 S in the lines-of-sight to these objects. The upper limits are found to be consistent with the proposal that H 2 S molecules are formed on grain surfaces and subsequently desorbed to re-supply the gas-phase.