We present an overview of, and first science results from, the Magellanic Edges Survey (MagES), an ongoing spectroscopic survey mapping the kinematics of red clump and red giant branch stars in the highly substructured periphery of the Magellanic Clouds. In conjunction with Gaia astrometry, MagES yields a sample of ~7000 stars with individual 3D velocities that probes larger galactocentric radii than most previous studies. We outline our target selection, observation strategy, data reduction and analysis procedures, and present results for two fields in the northern outskirts ($>10^{\circ}$ on-sky from the centre) of the Large Magellanic Cloud (LMC). One field, located in the vicinity of an arm-like overdensity, displays apparent signatures of perturbation away from an equilibrium disk model. This includes a large radial velocity dispersion in the LMC disk plane, and an asymmetric line-of-sight velocity distribution indicative of motions vertically out of the disk plane for some stars. The second field reveals 3D kinematics consistent with an equilibrium disk, and yields $V_{\text{circ}}=87.7\pm8.0$km s$^{-1}$ at a radial distance of ~10.5kpc from the LMC centre. This leads to an enclosed mass estimate for the LMC at this radius of $(1.8\pm0.3)\times10^{10}\text{M}_{\odot}$.

中文翻译：

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麦哲伦边缘调查 I：描述和初步结果

我们介绍了麦哲伦边缘巡天 (MagES) 的概述和第一批科学结果，这是一项正在进行的光谱巡天，绘制了麦哲伦星云高度亚结构外围中红团和红巨星分支星的运动学。与盖亚天体测量相结合，MagES 产生了大约 7000 颗恒星的样本，这些恒星具有单独的 3D 速度，比以前的大多数研究探测更大的半乳心半径。我们概述了我们的目标选择、观测策略、数据简化和分析程序，并展示了大麦哲伦云 (LMC) 北郊（从中心到天空的 $>10^{\circ}$）的两个场的结果. 一个位于臂状超密度附近的场显示出远离平衡盘模型的明显扰动特征。这包括 LMC 圆盘平面中的大径向速度弥散，以及指示某些恒星垂直离开圆盘平面的运动的不对称视线速度分布。第二个字段显示与平衡盘一致的 3D 运动学，并在距 LMC 约 10.5kpc 的径向距离处产生 $V_{\text{circ}}=87.7\pm8.0$km s$^{-1}$中心。这导致 LMC 在 $(1.8\pm0.3)\times10^{10}\text{M}_{\odot}$ 半径处的封闭质量估计。