SPECTRAL IRRADIANCE CALIBRATION IN THE INFRARED .5. THE ROLE OF UKIRT AND THE CGS3 SPECTROMETER

We describe, illustrate, and quantify the performance achieved by the combination of CGS3 and UKIRT, with emphasis on the role already played by CGS3 in the field of spectrally continuous, absolute, infrared radiance calibration. The focus of the paper is on the reliability and reproducibility of the spectral shapes obtained by CGS3. We offer an electronically available data base of calibration spectra taken with UKIRT and CGS3 of a variety of infrared-bright cool K and M giants. These highlight the influence of the SiO fundamental absorption on the stellar spectra as effective temperature is varied. The calibration archive has an absolute pedigree traceable directly to Cohen et al.