论文标题
射手座流中的球形簇。与Gaia DR2一起修改成员和候选人
Globular Clusters in the Sagittarius stream. Revising members and candidates with Gaia DR2
论文作者
论文摘要
我们使用GAIA DR2数据重新考虑了银河球状簇（GC）与射手座矮球球星系（SGR DSPH）的潮流相关的情况。我们使用RR Lyrae在6D中追踪流，然后选择与观察到的流相匹配的簇和速度。除了居住在星系主体（M 54，TER 8，TER 7，ARP 2）中的簇外，我们还确认了PAL 12和Whiting 1的成员资格和Whiting 1的成员降落到最近在近期周期通道中丢失的恒星所占的尾臂部分。 NGC 2419，NGC 5634和NGC 4147是非常有趣的候选人，可能与溪流的更古老的包裹有关。我们注意到，除了M 54以外，所有这些簇位于星系恒星核内，都在溪流的后臂中发现。所选的簇与[Fe/H]与[Mg/Fe]，[CA/Fe]模式以及SGR DSPH主体中田间星星显示的年龄金属关系完全一致。
We reconsider the case for the association of Galactic globular clusters (GCs) to the tidal stream of the Sagittarius dwarf spheroidal galaxy (Sgr dSph), using Gaia DR2 data. We use RR Lyrae to trace the stream in 6D and we select clusters matching the observed stream in position and velocity. In addition to the clusters residing in the main body of the galaxy (M 54, Ter 8, Ter 7, Arp 2) we confirm the membership of Pal 12 and Whiting 1 to the portion of the trailing arm populated by stars lost during recent perigalactic passages. NGC 2419, NGC 5634 and NGC 4147 are very interesting candidates, possibly associated to more ancient wraps of the stream. We note that all these clusters, with the exception of M 54, that lies within the stellar nucleus of the galaxy, are found in the trailing arm of the stream. The selected clusters are fully consistent with the [Fe/H] vs. [Mg/Fe], [Ca/Fe] patterns and the age-metallicity relation displayed by field stars in the main body of Sgr dSph.
