Wavelength Calibration of the Xinglong HRS with a Laser Frequency Comb Device of a Yb Fiber Laser

With expasion of applications of large-aperture telescopes and high-resolution echelle gratings, more accuate wavelength calibration is becoming increasingly important, and improving wavelength-calibration accuracies emerges as an urgent issue to be resolved. A newly intrduced technique is to use LFC (Laser Frequency Comb) devices to generate standard spectra for wavelength calibration. A standard spectrum from an LFC device not only has spectral lines of highly uniform intensities/wavelength intervals, but also makes it feasible to achieve higher precisions of radial-velocity measurements of various astrophysical objects (to be on the level of a few cm/s or the relative-error level of 10^-10). This should provide observational clues to a variety of important questions in astrophysics. In this paper we report the results of our first test of wavelength calibration of the Xinglong HRS (High-Resolution Spectrograph) of R-50000 by using an LFC device of a Yb fiber laser to generate the standard spectra. Our test focused on the performance of the HRS on 8 echelle orders (spanning about 550.0nm to about 590.0nm). The perforamce is measured in the characteristics of comb-line profiles and instrumental wavelength drifts. We have aslo compared our results to those of foreign research groups as preparations for optimizing and improving the LFC system.