Synthesising, using, and correcting for telluric features in high-resolution astronomical spectra

摘要

We present a technique to synthesise telluric absorption and emissionfeatures both for in-situ wavelength calibration and for their removal fromastronomical spectra. While the presented technique is applicable for a widevariety of optical and infrared spectra, we concentrate in this paper onselected high-resolution near-infrared spectra obtained with the CRIRESspectrograph to demonstrate its performance and limitation. We find thatsynthetic spectra reproduce telluric absorption features to about 2%, evenclose to saturated line cores. Thus, synthetic telluric spectra could be usedto replace the observation of telluric standard stars, saving valuableobserving time. This technique also provides a precise in-situ wavelengthcalibration, especially useful for high-resolution near-infrared spectra in theabsence of other calibration sources.