The Astrophysical Journal · 1994 · 130 citations · 0 references
Natural SciencesAstronomyPhysicsAstrophysicsOptical AstronomySpectroscopyInterstellar Absorption LinesInterstellar DustInterstellar Dust EmissionInterstellar GasStellar SpectroscopyAsymptotic Giant Branch StarsCircumstellar Dust EmissionDust Grain CompositionInterstellar Dust ModelsInterstellar Dust SpectroscopyIron SulfidesPlanetary NebulaeProtoplanetary Nebulae
In this Letter we communicate optical data of Mg-Fe sulfides in the wavelength range from 10 to 500 micrometer. The sulfides were prepared in our laboratory in order to test the tentative identification of a prominent circumstellar emission band at 30 micrometer observed in carbon-rich Asymptotic Giant Branch (AGB) stars, protoplanetary, and planetary nebulae with Mg-S vibrations in sulfide grains. Arguments in favor of the existence of an interstellar sulfide dust component consisting of FeS or iron-rich Mg-Fe sulfides are discussed. Model calculations for the source IRC +10216 based on the communicated optical data demonstrate their practical use. The possibilities for the observational detection of interstellar FeS bands are considered.