Properties of amorphous H2O ice and origin of the 3.1-micron absorption
Abstract
A study has been made of the optical constants of amorphous H2O ice in the 2.5-80 micron range. The range was selected for its relevance to astrophysics. The results are fit to a model of IR sources in molecular clouds. There is a good fit of the molecular cloud IR signature at 3.1-microns, assuming the grains are made of an intimate mixture of ice and silicate. A Mathis-like size distribution with a variable cut-off is assumed. A good fit is obtained for a 2/3 H2O, 1/3 NH3 spectral mixture with a large value of grain-size cut-off. This suggests that grains are much bigger in molecular clouds than in the low-density stellar medium.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1983
- Bibcode:
- 1983A&A...117..164L
- Keywords:
-
- Ice;
- Infrared Absorption;
- Infrared Spectra;
- Interstellar Matter;
- Line Spectra;
- Molecular Clouds;
- Absorption Spectra;
- Amorphous Materials;
- Optical Properties;
- Particle Size Distribution;
- Stellar Evolution;
- Astrophysics