Properties of Radial Velocities measurement based on LAMOST-II Medium-Resolution Spectroscopic Observations
Abstract
The radial velocity (RV) is a basic physical quantity which can be determined through Doppler shift of the spectrum of a star. The precision of RV measurement depends on the resolution of the spectrum we used and the accuracy of wavelength calibration. In this work, radial velocities of LAMOST-II medium resolution (R ~ 7500) spectra are measured for 1,594,956 spectra (each spectrum has two wavebands) through matching with templates. A set of RV standard stars are used to recalibrate the zero point of the measurement, and some reference sets with RVs derived from medium/high-resolution observations are used to evaluate the accuracy of the measurement. Comparing with reference sets, the accuracy of our measurement can get 0.0227 km s/1 with respect to radial velocities standard stars. The intrinsic precision is estimated with the multiple observations of single stars, which can achieve to 1.36 km s/1,1.08 km s/1, 0.91 km s/1 for the spectra at signal-to-noise levels of 10, 20, 50, respectively.
Keywords
Cite
@article{arxiv.1908.04773,
title = {Properties of Radial Velocities measurement based on LAMOST-II Medium-Resolution Spectroscopic Observations},
author = {R. Wang and A. -L. Luo and J. -J. Chen and Z. -R. Bai and L. Chen and X. -F. Chen and S. -B. Dong and B. Du and J. -N. Fu and Z. -W. Han and J. -L. Hou and Y. -H. Hou and W. Hou and D. -K. Jiang and X. Kong and L. -F. Li and C. Liu and J. -M. Liu and L. Qin and J. -R. Shi and H. Tian and H. Wu and C. -J. Wu and J. -W. Xie and H. -T. Zhang and S. Zhang and G. Zhao and Y. -H. Zhao and J. Zhong and W. -K. Zong and F. Zuo},
journal= {arXiv preprint arXiv:1908.04773},
year = {2019}
}
Comments
published by ApJs. 13 pages, 13 figures