| 其他摘要 | As one of the important means of astronomical observation in time domain, high dispersion spectroscopic observation is an important observation method in astrophysics research. It plays an important role in determining the parameters of late-type stars, binary systems, pulsating variables, comets and other celestial systems, as well as in the discovery and certification of lithium-rich stars, exoplanet detection, galaxy kinematics and other fields.The high dispersion fiber spectrometer (HiRES) equipped with the 2.4-meter telescope in Lijiang is an important instrument for high dispersion optical observation in China. In order to give full play to the observation performance of the equipment, this paper combines its present situation and existing problems, from the two angles of improving the observation ability and improving the observation quality, several key techniques to improve the accuracy of HiRES measurement are systematically studied, including the following four aspects:Firstly, aiming at the problems of HiRES system hardware, target authentication and pointing correction which affect the observation efficiency. A scheme of upgrading guide star system by multi-layer dielectric coating is proposed and realized, which can improve the energy collection ability of the observed target and increase the observable limit magnitude of guider from 12 to 15. The method of accurate target verification and direction correction based on Astrometry.net is studied. This method not only improves the HiRES observation limit magnitude, but also greatly improves the observation efficiency of the instrument.Secondly, a method of estimating CCD exposure in real time is studied and established by using Photomultiplier tube (PMT). By integrating PMT, the SNR of spectral observation is ensured, and the problem that CCD exposure is difficult to estimate and the quality of spectral data cannot be guaranteed in long integral spectral observation is solved. The main research contents of this part include: 1）The relationship between CCD exposure and exposure count is determined by analyzing the observed data of flat-field lamp spectra; 2）An estimation method of modeling according to spectral types is proposed, and a template library of conversion between CCD exposure and count values of six spectral types B,A,F,G,K and M is established, which is verified by practical observation data; 3） Integrating this method into the actual observation system, designing and implementing the upper computer operating software.Thirdly, the wavelength calibration process of ThAr lamp is studied, and a set of high-precision standardized processing scheme is formed. It overcomes the problem of using traditional complex interactive data processing software, such as non-uniform standards. The main research contents of this part include: 1） two-dimensional spectral Data pre-processing, 2） fast extraction of one-dimensional spectra based on template matching, 3） wavelength calibration of one-dimensional spectra, re-establishment and optimization of the characteristic spectral line library, 4） spectral line selection and high-precision measurement, wavelength calibration fitting, and special-order calibration.Fourthly, the error analysis and correction method for the stability of ThAr lamp are studied. The main research contents of this part include: 1） measuring the position shift and wavelength shift of spectral order by using measured spectra; 2）A complete environmental monitoring system was designed and deployed at different positions in the spectrometer room, and it was found that there was a significant correlation between wavelength drift and internal pressure variation of the spectrometer; 3）The model of internal pressure and wavelength shift is established, and the model is used to correct the spectral line shift. The correction accuracy for an observation night can reach<0.0002nm. By using this model, wavelength shift can be calculated according to the real-time measured values of atmospheric pressure collected, and then observation efficiency and accuracy can be improved.On the one hand, the research contents and the corresponding results of this thesis have significantly improved the observation capability, observation quality, observation efficiency and wavelength calibration accuracy of the high dispersion spectrum of the Lijiang 2.4 m telescope, on the other hand, it also realizes the standardization of the spectral data processing flow, which contributes to the further development of the instrument's comprehensive performance and the improvement of scientific output. |
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