CRIRES: Reference frames

CRIRES reference frames

The CRIRES reference frames pages offer:

• example frames for the daily health check settings (plus selected additional settings)
• an atlas of ThAr and N2O wavelength calibration exposures
• S/N in flat fields.

Wavelength calibration atlas

CRIRES offers dedicated measurements for wavelength calibration which use either a ThAr arc lamp or an N2O gas absorption cell. The number of available spectral lines on each of the four detectors strongly depends on the setting. This page provides an atlas of actually measured calibrations which can be used to infer the number of available lines in a given setting or for comparison with recently taken frames.

The atlas has been collected from regular operations in October and November 2009. The images show cuts of the raw frames in dispersion direction for each detector. The positions of lines from the catalogs are indicated. Cross-correlation values from the standard pipeline wavelength calibration are also given (as "xcorr=", a value of -1 indicates that the wavelength calibration was not successful for that detector).

Please choose from the menus below the reference wavelength of a setting for either a ThAr or an N2O exposure. For detailed inspection, it is possible to click on each image for a full view.

ThAr exposures

The images show row averages. Weak lines are sometimes not visible in these images, but the cross-correlation value about the quality of the wavelength solution for a particular setting and detector. ThAr line positions are indicated by vertical red lines. Regions that are not exposed from the respective order (and which can be contaminated by adjacent orders) are idicated by gray-shaded areas in the plots.

N2O exposures

A cut along the central row is shown. The reference N2O absorption line spectrum is shown as a continuous blue line.