Tools and Tips
CRIRES-specific tools
Catalogues of telluric standard stars:
- Hipparcos A1 stars or earlier, suitable for J, H, K, and L bands spectroscopy
- Hipparcos B8 or earlier with V <4.0 or B8 to G0 with V < 4.8, suitable for M-band spectroscopy
- Hipparcos O type stars (from ISAAC)
- Hipparcos B type stars (from ISAAC)
- Hipparcos G type stars (from ISAAC)
Catalogues of spectro-photometric standard stars:
-
Optical Spectrophotometric Standards of SpT B4-A9.
Models for these stars in the range 950 to 5466 nm are collected in this
gzipped FITS binary file, part of the
static calibration frames (19.3 MB).
Line lists:
- Calibration tables from NIST. This link provides wavenumbers for a number of molecules, useful to calibrate CRIRES spectra either from atmospheric lines or with gas-cells. In wavenumber, CRIRES spectral range is [1850 - 10520 ]/cm. Currently, the installed gas-cells contain N2O and CO, respectively. A gas-cell containing OCS should be available in the near future.
- An ESO-NIST collaboration lead to doubling the number of ThAr lines: see Kerber, F., Nave, G. & Sansonetti, C.J 2008 accepted for publication in ApJ. This paper should be cited by users whose science benefitted from this ThAr line list.
- Additional line lists are part of the static calibration frames (19.3 MB). See the CRIRES calibration data for details. Note in particular that the ThAr line list should be soon replaced by a new version that includes the lines identified by Kerber et al.
CRIRES pipeline:
-
The CRIRES pipeline is available for download.
Correction of non-linearity, including the odd-even effect:
-
Correcting both the flat-field and the science data from departure of
linearity allows one to reduce the odd-even effect to an unnoticeable
level.
Reference files have been created that contain the coefficients
a
b
c
of the relation
I_corrected = [-bē +bē sqrt[1 - 4 c (a - I_orig)/bē]]/(2 c)
for each pixel of each detector, where I_orig is the raw intensity after subtraction of the dark, and I_corrected is the intensity corrected for non-linear effects. Note that data (including flat-field) obtained with a DIT < 2 s suffer from a different type of non-linear effects, caused by the finite reset time of the detector arrays. Therefore such DIT should be avoided. See science recipes , or more generally, the CRIRES pipeline: general description for more information.