| Abstract
| - Context. The ν2 bending mode of pure CO 2 ice around 15.2 μm exhibits a fine double-peak structure that offers a sensitive probe to study the physical and chemical properties of solid CO 2 in space. Current laboratory spectra do not fully resolve the CO 2 ice features. Aims. To improve the fitting of the observed CO 2 features, high-resolution solid-state infrared spectra of pure CO 2 ice are recorded in the laboratory for a series of astronomically relevant temperatures and at an unprecedented level of detail. Methods. The infrared spectra of pure CO 2 ice were recorded in the 4000 to 400 cm -1 (2.5-25 μm) region at a resolution of 0.1 cm -1 using Fourier transform infrared spectroscopy. Results. Accurate band positions and band widths (FWHM) of pure CO 2 ice are presented for temperatures of 15, 30, 45, 60, and 75 K. The focus of this spectroscopic work is on the CO 2 ( ν2) bending mode, but more accurate data are also reported for the 12CO 2 and 13CO 2 ( ν3) stretching mode, and CO 2 ( ν1+ ν3) and (2 ν2+ ν3) combination bands.
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