Infrared observations of ices and silicates in molecular clouds

Abstract

view Abstract Citations (193) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Infrared observations of ices and silicates in molecular clouds. Merrill, K. M. ; Russell, R. W. ; Soifer, B. T. Abstract Spectrophotometric observations from 2 to 4 microns and from 8 to 13 microns of several infrared sources associated with molecular clouds are reported. Narrow absorption features at 3.08 microns, attributed to interstellar ices, appear in all sources with a molecular cloud in the intervening line of sight. All sources showing ice absorptions also show broad absorption features, attributed to cold silicates, from 8 to 13 microns. The observed ice absorption profiles are all quite similar; however, they do not fit in detail Mie theory predictions of extinction for pure H2O or NH3 ices. The ratio of ice-to-silicate optical depths is found to vary, with most sources showing a ratio in the range 0.1-0.4. The ratio of visual extinction to ice absorption is found to increase rapidly from inside to outside the molecular cloud in NGC 2024. Publication: The Astrophysical Journal Pub Date: August 1976 DOI: 10.1086/154545 Bibcode: 1976ApJ...207..763M Keywords: Ice; Infrared Astronomy; Interstellar Matter; Molecular Absorption; Silicates; Absorption Spectra; Ammonia; Electromagnetic Absorption; Interstellar Extinction; Mie Scattering; Solid Phases; Water; Astrophysics full text sources ADS |