论文标题
NGC 7089（M2）的延伸潮汐尾
The Extended Tidal Tails of NGC 7089 (M2)
论文作者
论文摘要
使用Gaia早期数据发行3的光度法和适当的运动，我们检测到与旧的，金属贫困的球状球形群集NGC 7089相关的45度落后恒星碎片流。在100 pc的范围内，宽度的宽度似乎与发现的最冷的已知流相同。有一些证据表明，延伸的前导尾巴距离群集在28至37度之间，尽管该尾巴的距离较大，结合了与前景恒星几乎没有区别的正确运动，但要确定检测要确定得多。使用的简单银河电位纯粹由磁盘，凸起和球形光环组成，因此无法很好地匹配后尾尾的天空的适当动作曲线和路径。然而，增加移动的大量（M = 1.88 x 10^（11）太阳能物质）大麦芽云使模型预测与可观察物的一致性更好。我们提供了最排名最高的候选溪流星的表，以进行持续和未来的光谱调查。
Using photometry and proper motions from Gaia Early Data Release 3, we detect a 45 degree-long trailing stellar debris stream associated with the old, metal-poor globular cluster NGC 7089. With a width on the order of 100 pc, the extended stream appears to be as dynamically cold as the coldest known streams found to date. There is some evidence for an extended leading tail extending between 28 and 37 degrees from the cluster, though the greater distance of this tail, combined with proper motions that are virtually indistinguishable from those of foreground stars, make the detection much less certain. The proper motion profile and the path on the sky of the trailing tail are not well matched using a simple Galactic potential comprised purely of a disk, bulge, and spherical halo. However, the addition of a moving, massive (M = 1.88 x 10^(11) solar masses) Large Magellanic Cloud brings the model predictions into much better agreement with the observables. We provide tables of the most highly ranked candidate stream stars for follow-up by ongoing and future spectroscopic surveys.
