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Updated: Jun 30, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Spectroscopic detection of molecular hydrogen frozen in interstellar ices
S A Sandford1, L J Allamandola, T R Geballe
1NASA/Ames Research Center, Moffett Field, CA 94035, USA.
Abstract:
A weak infrared absorption feature near 4141 wavenumbers (2.415 micrometers) in the spectrum of WL5, an infrared source in the rho Ophiuchus cloud complex, has been detected. It is attributed to molecular hydrogen created by irradiation and frozen in situ into water-rich ices. A second, broader absorption at 4125 wavenumbers centimeters (2.424 micrometers) is probably due to methanol in the ices. The column densities of frozen molecular hydrogen and methanol are inferred to be about 2.5 x 10(18) and 3.0 x 10(19), respectively. There is about three times more frozen molecular hydrogen than frozen carbon monoxide along this line of sight.
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