J/A+A/555/A85 Resolved IR spectra of pure CO2 ice (15-75K) (Isokoski+, 2013)
Highly resolved infrared spectra of pure CO2 ice (15-75 K).
Isokoski K., Poteet C.A., Linnartz H.
<Astron. Astrophys. 555, A85 (2013)>
=2013A&A...555A..85I 2013A&A...555A..85I
ADC_Keywords: Spectra, infrared ; Line Profiles ; Interstellar medium
Keywords: astrochemistry - line: profiles - methods: laboratory -
techniques: spectroscopic - ISM: lines and bands - ISM: molecules
Abstract:
The v2 bending mode of pure CO2 ice around 15.2um exhibits a fine
double-peak structure that offers a sensitive probe to study the
physical and chemical properties of solid CO2 in space. Current
laboratory spectra do not fully resolve the CO2 ice features.
To improve the fitting of the observed CO2 features, high-resolution
solid-state infrared spectra of pure CO2 ice are recorded in the
laboratory for a series of astronomically relevant temperatures and at
an unprecedented level of detail.
The infrared spectra of pure CO2 ice were recorded in the 4000 to
400cm-1 (2.5-25um) region at a resolution of 0.1cm-1 using Fourier
transform infrared spectroscopy.
Accurate band positions and band widths (FWHM) of pure CO2 ice are
presented for temperatures of 15, 30, 45, 60, and 75K. The focus of
this spectroscopic work is on the CO2 (v2) bending mode, but more
accurate data are also reported for the 12CO2 and 13CO2 (v3)
stretching mode, and CO2 (v1+v3) and (2v2+v3) combination bands.
Description:
Highly resolved (0.1cm-1) transmission infrared spectra of pure
CO2 ice at 15, 30, 45, 60 and 75K.
Experimental details: Normal vapor deposition of pure CO2 gas
(99.998% purity), substrate temperature during deposition = 15.
K, deposition rate ∼10L/s (1L = Langmuir = 1x10-6Torr s = 1ML), ice
thickness ∼3000ML, heating rate 2K/min. Spectra corresponding to
different temperatures are different samples prepared through
identical procedure.
Spectral details: spectral range 4000-400cm-1, resolution 0.1cm-1,
scans averaged 256, duration of scan ∼2 hours. Background recorded at
15K prior to sample deposition, subtracted from all spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 83 26 List of spectra
spec/* 29 26 Individual spectra
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See also:
VI/111 : ISO Observation Log (ISO Data Centre, 2004)
J/A+A/390/1033 : The ISO-SWS post-helium atlas (Vandenbussche+, 2002)
J/ApJ/743/131 : Interstellar water ice formation (Smith+, 2011)
J/ApJS/86/713 : IR spectroscopy of ices (Hudgins+, 1993)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 21 A21 --- Type Type of spectrum: "Raw spectrum",
"Baseline subtracted" or "Spectrum of gas phase"
23- 34 A12 --- Corr Correction or smoothing methods (1)
36- 42 A7 --- CO2 "ice", "v2" or "v3" mode
44- 46 I3 K T [15/300] Temperature
49- 52 I4 cm-1 sig.0 Lower wavenumber in the spectrum
55- 58 I4 cm-1 sig.1 Upper wavenumber in spectrum
61- 83 A23 --- FileName Name of the file containing the spectrum,
in subdirectory spec
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Note (1): "corr. CO2(g)" for (ν3): In the laboratory, the CO2 ice
feature around 2350cm-1 is easily contaminated with absorptions of
gaseous CO2 along the IR beam path. The spectra are corrected using
a gaseous CO2 spectrum extracted from the background spectrum. See
Fig. 6 and section 3.1 for further explanations. "smoothed": spectra
are obtained by smoothing through superposition of Gaussians.
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Byte-by-byte Description of files: spec/*
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Bytes Format Units Label Explanations
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1- 10 F10.5 cm-1 sigm frequency in wave numbers
15- 29 E15.6 --- Abs ? Absorbance
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Acknowledgements:
Karoliina Isokoski: <isokoski{at}strw.leidenuniv.nl>
(End) Karoliina Isokoski [Univ. Leiden], Emmanuelle Perret [CDS] 05-Jul-2013