标题： 潮汐流中的子结构；反中心环中的支流 显示英文标题

标题： Substructure in Tidal Streams; Tributaries in the Anticenter Ring

摘要： 我们报告在斯隆数字天空调查数据中检测到至少三个大致平行的组成部分，这些组成部分是之前用反中心或单峰星环识别出的65度长的恒星流复合体。 三股流复合体的宽度沿其长度从4到6度不等，似乎由两个或更多狭窄的子流以及一个更宽广、弥散的成分组成。 流的宽度和复杂性表明，原始天体很可能是一个显著大小和质量的矮星系。 该流距离地球8.9千秒差距，并且几乎垂直于我们的视线方向。 可见部分的流并不靠近任何已知的矮星系，初步轨道也不指向任何可行的原始天体候选者。 较窄的子流的轨道可以用相对于宽成分约8公里/秒的速度偏移来建模。 我们认为，宽成分可能是矮星系的残余物，而较窄的流则构成动态不同的组成部分的残余物，这些组成部分可能包括本地的球状星团种群。 尽管主序转折点的颜色与单峰星环相似，但可见流或其轨道的任何合理投影都不经过单峰星或猎户座，因此我们得出结论，这条流可能与这些区域发现的密度增强无关。 显示英文摘要

摘要： We report on the detection in Sloan Digital Sky Survey data of at least three, roughly parallel components in a 65 degree-long stellar stream complex previously identified with the Anticenter or Monoceros Ring. The three-stream complex varies in width from 4 to 6 degrees along its length and appears to be made up of two or more narrow substreams as well as a broader, diffuse component. The width and complexity of the stream indicate that the progenitor was likely a dwarf galaxy of significant size and mass. The stream is 8.9 kpc distant and is oriented almost perpendicularly to our line of sight. The visible portion of the stream does not pass near any known dwarf galaxies and a preliminary orbit does not point to any viable progenitor candidates. Orbits for the narrower substreams can be modeled with velocity offsets from the broad component of about 8 km/s. We suggest that the broad component is likely to be the remains of a dwarf galaxy, while the narrower streams constitute the remnants of dynamically distinct components which may have included a native population of globular clusters. While the color of the main sequence turn-off is not unlike that for the Monoceros Ring, neither the visible stream nor any reasonable projection of its orbit passes through Monoceros or Canis Major, and we conclude that this stream is probably unrelated to the overdensities found in these regions.