Constraints on the abundances of various molecules in interstellar ice: laboratory studies and astrophysical implications

Publication

Reference: Boudin N., Schutte W. A., Greenberg J. M. (1998). Constraints on the abundances of various molecules in interstellar ice: laboratory studies and astrophysical implications. Astron. Astrophys., 331, 749 - 759.

Names

Title: Constraints on the abundances of various molecules in interstellar ice: laboratory studies and astrophysical implications
Abstract: Ethane, acetylene, ethanol, hydrazine and hydrogen peroxide are either predicted by theoretical models to be abundant in the icy mantles on grains in dense clouds, or were found to be produced by comets. We present measurements of the spectra of these species embedded in astrophysically relevant ice matrices. Additionally, we obtained the spectrum of the hydrozonium ion ($N_2H_5^+$) which could be produced by activation less acid- base reactions. The laboratory results are compared to the ISO and ground-based spectra of NGC 7538:IRS 9. Strict upper-limits compared to the solid water could be found for ethane, ethanol and hydrogen peroxide of <0.4%, <1.2%, and <6.1%, respectively. These results give some important information on the relationship between cometary and interstellar ices and on the nature of grain surface reactions.
Keywords: spectroscopy, transmission spectra, absorbance spectra, band position, band width, band vibration mode, band integrated intensity, band strength, mid-IR, molecular solid, amorphous, ice, mixture, C2H2, C2H6, CH3CH2OH, H2O2, N2H4, N2H5+, C2H2, H2O, CO
Content: spectral data, band list data, experimental physics

Identifiers