论文标题
在径向速度校准中
On the radial velocity calibrations in the LAMOST Medium-Resolution Spectroscopic Survey of Nebulae
论文作者
论文摘要
光学发射线的准确径向速度确定（即[NII] $λλ$ 6548,6584，H $α$和[SII] $λλ$ 6717,6731）对于研究Nebulae的运动学和动力学特性非常重要。大型天空区域多对象纤维光谱望远镜（Lamost）的第二阶段调查计划已经开始了星云（MRS-N）的子调查，该调查将从光谱上观察到银河系平面附近的大型星云样本的光学发射线。到目前为止，从2017年9月至2019年6月，已经观察到15个MRS-N板。基于MRS-N红色带光谱中的天空发射线的拟合，我们研究了波长校准的精度，发现不同板的径向速度（RV）系统偏差从$ \ sim $ \ sim $ \ sim $ \ 4 km/s。特别是对于2018年3月获得的板，RVS的系统偏差可能高达$ \ sim $ 4 km/s/s，然后在2018年底和2019年1月底下降到$ \ sim $ \ sim $ \ sim $ \ sim $ \ sim $ \ sim $ \ sim $ \ sim $ \ sim $ \ sim $ \ sim。
Accurate radial velocity determinations of optical emission lines (i.e. [NII]$λλ$6548,6584, H$α$, and [SII]$λλ$6717,6731) are very important for investigating the kinematics and dynamics properties of nebulae. The second stage survey program of Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) has started a sub-survey of nebulae (MRS-N) which will spectroscopically observe the optical emission lines of a large sample of nebulae near the Galactic plane. Until now, 15 MRS-N plates have been observed from 2017 September to 2019 June. Based on fitting the sky emission lines in the red band spectra of MRS-N, we investigate the precision of wavelength calibration and find there are systematic deviations of radial velocities (RVs) from $\sim$0.2 to 4 km/s for different plates. Especially for the plates obtained in 2018 March, the systematic deviations of RVs can be as large as $\sim$4 km/s, which then go down to $\sim$0.2-0.5 km/s at the end of 2018 and January 2019. A RVs calibration function is proposed for these MRS-N plates, which can simultaneously and successfully calibration the systematic deviations and improve the precision of RVs.
