LAMOST Medium-Resolution Spectral Survey of Galactic Nebulae (LAMOST-MRS-N): Subtraction of Geocoronal Halpha Emission

On the radial velocity calibrations in the LAMOST Medium-Resolution Spectroscopic Survey of Nebulae

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…

Self-consistent Stellar Radial Velocities from LAMOST Medium-Resolution Survey (MRS) DR7

Radial velocity (RV) is among the most fundamental physical quantities obtainable from stellar spectra and is rather important in the analysis of time-domain phenomena. The LAMOST Medium-Resolution Survey (MRS) DR7 contains 5 million single-exposure stellar spectra at spectral resolution $R\sim7\,500$. However, the temporal variation of the RV zero-points (RVZPs) of the MRS survey, which makes the RVs from multiple epochs inconsistent, has not been addressed. In this paper, we measure the RVs of the 3.8 million single-exposure spectra (for 0.6 million stars) with signal-to-noise ratio (SNR) hi…

The Spectroscopic Binaries from LAMOST Medium-Resolution Survey (MRS). I. Searching for Double-lined Spectroscopic Binaries (SB2s) with Convolutional Neural Network

We developed a convolutional neural network (CNN) model to distinguish the double-lined spectroscopic binaries (SB2s) from others based on single exposure medium-resolution spectra ($R\sim 7,500$). The training set consists of a large set of mock spectra of single stars and binaries synthesized based on the MIST stellar evolutionary model and ATLAS9 atmospheric model. Our model reaches a novel theoretic false positive rate by adding a proper penalty on the negative sample (e.g., 0.12\% and 0.16\% for the blue/red arm when the penalty parameter $Λ=16$). Tests show that the performance is as exp…

基于Gaia和APOGEE的LAMOST MRS的两级视向速度零点校准及增值视向速度星表

A Two-level Radial-velocity Zero-point Calibration for LAMOST MRS with Gaia and APOGEE and a Value-added RV Catalogue

该研究针对LAMOST MRS的RV零点系统误差，提出两级校准方法并发布增值星表，使RV精度提升约2倍，支持跨多维度的一致视向速度分析。

在LAMOST-MRS数据中识别由月光污染导致的假阳性双星谱线双星

Identification of false positive double-lined spectroscopic binaries in LAMOST-MRS data due to moonlight contamination

本文提出了一种方法，通过分析LAMOST-MRS数据，识别由月光污染导致的假阳性双星谱线双星，并确定了影响月光污染的关键因素。

Phase II of the LAMOST-Kepler/K2 survey. I. Time series of medium-resolution spectroscopic observations

Phase \RNum{2} of the LAMOST-{\sl Kepler/K}2 survey (LK-MRS), initiated in 2018, aims at collecting medium-resolution spectra ($R\sim7,500$; hereafter MRS) for more than $50,000$ stars with multiple visits ($\sim60$ epochs) over a period of 5 years (2018 September to 2023 June). We selected 20 footprints distributed across the {\sl Kepler} field and six {\sl K}2 campaigns, with each plate containing a number of stars ranging from $\sim2,000$ to $\sim 3,000$. During the first year of observations, the LK-MRS has already collected $\sim280,000$ and $\sim369,000$ high-quality spectra in the blue …

利用人机混合方法在LAMOST中分辨率光谱巡天中挖掘双线光谱候选体

Mining double-line spectroscopic candidates in the LAMOST medium-resolution spectroscopic survey using human-AI hybrid method

本文提出传统CCF与机器学习相结合的人机混合方法，在LAMOST-MRS DR9中高效识别出7096个SB2和1903个SB3候选体，并将目视检查时间缩短四倍。

LAMA：LAMOST中分辨率光谱分析流水线

LAMA: LAMOST Medium-Resolution Spectral Analysis Pipeline

LAMA是为LAMOST中分辨率光谱设计的恒星参数测量流水线，采用模板匹配方法，精度高且无偏差，已成功应用于近50万颗恒星，助力银河系研究。

新的紧凑型三合星系统：使用 LAMOST-MRS 光谱和测光发现相接双星周围的明亮第三星

The new compact triple system: discovery of bright third star around contact binary using LAMOST-MRS spectra and photometry

本研究利用 LAMOST-MRS 光谱和测光数据发现了一个罕见的层级三合星系统，其中第三星比内部相接双星更亮。通过提取三组件径向速度并结合光程时间效应联合拟合轨道，提出了测量相接系统周期和最小质量的经验方法。