User Manual
Doc. Number: ESO-323064
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3.2.3.1 Gas cells
The CRIRES science cases also demand specialized, highly accurate wavelength
calibration techniques. Therefore, another part of the upgrade is concerned with the
installation of novel IR absorption gas cells with multi-species gas fillings (NH
3
,
13
CH
4
, C
2
H
2
).
These gases will provide a set of densely distributed absorption lines imprinted on the stellar
spectra in the
H
- and
K
-bands (see Figure 17). In addition, the existing Thorium Argon
hollow cathode lamp is replaced with similar Uranium-Neon lamp that produce a richer
wavelength calibration spectrum.
Figure 17: Spectral coverage of the new short gas cell (SGC) in the H and K bands (top)
and the N
2
O gas cell in the L and M bands (bottom).