论文标题
安提斯（Antaeus）：银河系磁盘平面中的潮汐碎片逆行组
Antaeus: a retrograde group of tidal debris in the Milky Way's disk plane
论文作者
论文摘要
我们使用从\ textit {gaia} dr3目录中得出的动作角度坐标，在银河系磁盘平面上发现了一个宽逆行移动组。该结构是从目前几乎位于其轨道的偏生中并穿过太阳能邻里的一个成员的样本中识别出来的。该组中恒星的运动高度相关，表明该系统可能不是相混杂的。这种结构的宽度至少为1.5 kpc，并且可能具有金属性的内在散布，这种结构很可能是潮汐破裂的古代矮人银河系的潮流（年龄$ \ sim 12 $ gyr，$ \ \ langle，$ \ langle {\ rm [fe/h]} \ rangle \ rangle \ sim -1.74 $）。该结构与红杉合并事件相似（例如能量，角动量，金属性和偏心率）。但是，它具有极低的垂直动作$ J_Z $，即使在红杉动力组中，它也使其与众不同。由于低$ j_z $可能归因于动态摩擦，因此我们推测这些恒星可能是红杉祖细胞密集核心的残余物。
We present the discovery of a wide retrograde moving group in the disk plane of the Milky Way using action-angle coordinates derived from the \textit{Gaia} DR3 catalog. The structure is identified from a sample of its members that are currently almost at the pericenter of their orbit and are passing through the Solar neighborhood. The motions of the stars in this group are highly correlated, indicating that the system is probably not phase mixed. With a width of at least 1.5 kpc and with a probable intrinsic spread in metallicity, this structure is most likely the wide remnant of a tidal stream of a disrupted ancient dwarf galaxy (age $\sim 12$ Gyr, $\langle {\rm [Fe/H]} \rangle \sim -1.74$). The structure presents many similarities (e.g. in energy, angular momentum, metallicity, and eccentricity) with the Sequoia merging event. However, it possesses extremely low vertical action $J_z$ which makes it unique even amongst Sequoia dynamical groups. As the low $J_z$ may be attributable to dynamical friction, we speculate that the these stars may be the remnants of the dense core of the Sequoia progenitor.
