论文标题
Typhon：外光环下雨的极地溪流穿过太阳能街区
Typhon: a polar stream from the outer halo raining through the Solar neighborhood
论文作者
论文摘要
我们报告了GAIA DR3天文和光谱目录中的发现，该目录是一种新的极性流，该流是动作空间中的过度密度。这种结构是独一无二的，因为它具有极大的启动距离，达到100 kpc以上，但被检测为在太阳能社区中的连贯移动结构，宽度为$ \ sim 4 $ kpc。这些恒星的子样本被Lamost观察到了$ \ langle {\ rm [fe/h]} \ rangle = -1.60^{+0.15} _ { - 0.16} $ dex $ dex $ dex，并拥有$ n Metallic y $ ym ym ym ym n $ n { 0.32^{+0.17} _ { - 0.06} $ dex。流的物理宽度，金属性分散和垂直作用扩展表明祖细胞是矮星系。在太阳附近的周围中心存在这种连贯和高度径向的结构，这表明许多其他矮星系片段可能潜伏在外光环中。
We report on the discovery in the Gaia DR3 astrometric and spectroscopic catalog of a new polar stream that is found as an over-density in action space. This structure is unique as it has an extremely large apocenter distance, reaching beyond 100 kpc, and yet is detected as a coherent moving structure in the Solar neighborhood with a width of $\sim 4$ kpc. A sub-sample of these stars that was fortuitously observed by LAMOST has a mean spectroscopic metallicity of $\langle {\rm [Fe/H]}\rangle = -1.60^{+0.15}_{-0.16}$ dex and possesses a resolved metallicity dispersion of $σ({\rm [Fe/H]}) = 0.32^{+0.17}_{-0.06}$ dex. The physical width of the stream, the metallicity dispersion and the vertical action spread indicate that the progenitor was a dwarf galaxy. The existence of such a coherent and highly radial structure at their pericenters in the vicinity of the Sun suggests that many other dwarf galaxy fragments may be lurking in the outer halo.
