FIRST INFRARED BAND STRENGTHS FOR AMORPHOUS CO{sub 2}, AN OVERLOOKED COMPONENT OF INTERSTELLAR ICES

Journal Article · Sat Aug 01 04:00:00 EDT 2015 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/808/2/L40· OSTI ID:22518917

Gerakines, Perry A.

Solid carbon dioxide (CO{sub 2}) has long been recognized as a component of both interstellar and solar system ices, but a recent literature search has revealed significant qualitative and quantitative discrepancies in the laboratory spectra on which the abundances of extraterrestrial CO{sub 2} are based. Here we report new infrared (IR) spectra of amorphous CO{sub 2}-ice along with band intensities (band strengths) of four mid-IR absorptions, the first such results in the literature. A possible thickness dependence for amorphous-CO{sub 2} IR band shapes and positions also is investigated, and the three discordant reports of amorphous CO{sub 2} spectra in the literature are addressed. Applications of our results are discussed with an emphasis on laboratory investigations and results from astronomical observations. A careful comparison with earlier work shows that the IR spectra calculated from several databases for CO{sub 2} ices, all ices being made near 10 K, are not for amorphous CO{sub 2}, but rather for crystalline CO{sub 2} or crystalline-amorphous mixtures.

• OSTI ID: 22518917
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 808; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
ABSORPTION SPECTROSCOPY
CARBON DIOXIDE
COMPARATIVE EVALUATIONS
ELEMENT ABUNDANCE
ICE
INFRARED SPECTRA
INTERSTELLAR GRAINS
MIXTURES
MOLECULES
PLANETS
SATELLITES
SOLAR SYSTEM