论文标题
DESI银河系调查的概述
Overview of the DESI Milky Way Survey
论文作者
论文摘要
我们描述了将使用Kitt Peak National天文台的Mayall 4M望远镜上的黑暗能源光谱仪（DESI）进行的银河系调查（MWS）。在接下来的5年中，DESI MWS将在银河纬度| B |> 20度上观察到大约700万颗恒星，其中包含目标选择方案集中在厚磁盘和恒星光环上。 MWS还将包括几种罕见恒星类型的高完整度样本，包括白矮人，100pc之内的低质量恒星和水平分支星星。我们总结了DESI提高对银河结构和恒星进化的理解的潜力。我们介绍了主要MWS目标类别的最终定义，并估计将要观察到的每个类中的恒星数量。我们描述了导致径向速度，大气参数和化学丰度的管道。我们使用来自DESI调查验证程序（SV）的唯一恒星靶标的〜500,000个光谱，以证明我们的管道可以测量径向速度为〜1 km/s，并且[Fe/H]准确至〜0.2 DEX至〜0.2 DEX，对于我们的主要样品中的典型恒星。我们发现，从〜100平方英尺的SV观测值中的恒星参数分布在我们的主要样本上的完整性> 90％，与模拟目录和以前的调查的期望非常吻合。
We describe the Milky Way Survey (MWS) that will be undertaken with the Dark Energy Spectroscopic Instrument (DESI) on the Mayall 4m telescope at the Kitt Peak National Observatory. Over the next 5 yr DESI MWS will observe approximately seven million stars at Galactic latitudes |b|>20 degrees, with an inclusive target selection scheme focused on the thick disk and stellar halo. MWS will also include several high-completeness samples of rare stellar types, including white dwarfs, low-mass stars within 100pc of the Sun, and horizontal branch stars. We summarize the potential of DESI to advance understanding of Galactic structure and stellar evolution. We introduce the final definitions of the main MWS target classes and estimate the number of stars in each class that will be observed. We describe our pipelines for deriving radial velocities, atmospheric parameters, and chemical abundances. We use ~500,000 spectra of unique stellar targets from the DESI Survey Validation program (SV) to demonstrate that our pipelines can measure radial velocities to ~1 km/s and [Fe/H] accurate to ~0.2 dex for typical stars in our main sample. We find the stellar parameter distributions from ~100 sq. deg of SV observations with >90% completeness on our main sample are in good agreement with expectations from mock catalogs and previous surveys.
