Calibration Sources for CRIRES

We report on our efforts to provide high accuracy wavelength calibration to the scientific observations with the Cryogenic High-Resolution IR Echelle Spectrograph (CRIRES), ESO's new high resolution (R approximate to 100,000) infrared (IR) spectrograph at the VLT. In order to provide reliable and accurate wavelength standards for MIRES the European Southern Observatory (ESO), in collaboration with the Space Telescope European Co-ordinating Facility (ST-ECF) and the National Institute of Standards and Technology (NIST), embarked on a project to establish Th-Ar wavelength standards in the 950 nm to 5000 nm operating range of MIRES. In addition, and for use at wavelengths larger than 2200 nm, we have established a gas cell filled with N2O as a calibration source based on existing data from NIST. Both sources were extensively tested during MIRES commissioning runs and both are now being used for routine operations of the instrument.