LAMOST Time-Domain survey:first results of four K2 plates

• 作者: Song Wang Hao-Tong Zhang Zhong-Rui Bai Hai-Long Yuan Mao-Sheng Xiang Bo Zhang Wen Hou Fang Zuo Bing Du Tan-Da Li Fan Yang Kai-Ming Cui Yi-Lun Wang Jiao Li Mikhail Kovalev Chun-Qian Li Hao Tian Wei-Kai Zong Heng-Geng Han Chao Liu A-Li Luo Jian-Rong Shi Jian-Ning Fu Shao-Lan Bi Zhan-Wen Han Ji-Feng Liu
• 来源期刊: 天文和天体物理学研究
• 年，卷（期）: 2021,（11）
• 页码范围: 213-232
• 页数: 20页
• 语种: 英文
• DOI: 10.1088/1674-4527/21/11/292

摘要

From Oct.2019 to Apr.2020,LAMOST performed a time-domain(TD)spectroscopic survey of four K2 plates with both low-and medium-resolution observations.The low-resolution spectroscopic survey acquired 282 exposures(≈46.6 h)over 25 nights,yielding a total of about 767 000 spectra,and the medium-resolution survey took 177 exposures(≈49.1 h)over 27 nights,collecting about 478000 spectra.More than 70％/50％of low-resolution/medium-resolution spectra have signal-to-noise ratio higher than 10.We determine stellar parameters(e.g.,Teff,log g,[Fe/H])and radial velocity(RV)with different methods,including LASP,DD-Payne and SLAM.In general,these parameter estimations from different methods show good agreement,and the stellar parameter values are consistent with those of APOGEE.We use the Gaia DR2 RV values to calculate a median RV zero point(RVZP)for each spectrograph exposure by exposure,and the RVZP-corrected RVs agree well with the APOGEE data.The stellar evolutionary and spectroscopic masses are estimated based on the stellar parameters,multi-band magnitudes,distances and extinction values.Finally,we construct a binary catalog including about 2700 candidates by analyzing their light curves,fitting the RV data,calculating the binarity parameters from medium-resolution spectra and cross-matching the spatially resolved binary catalog from Gaia EDR3.The LAMOST TD survey is expected to represent a breakthrough in various scientific topics,such as binary systems,stellar activity,stellar pulsation,etc.