The Properties of Globular Clusters and Elqui Associated with the Sagittarius Dwarf Galaxy

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Abstract
To identify globular clusters (GCs) belonging to Sagittarius, we conducted verification from multiple aspects and carried out a detailed analysis of member GCs and the associated objectives. From the cluster catalog of E. L. Hunt & S. Reffert, we obtain the candidates of Sagittarius through the geometric space with proper motion ( μ α , μ δ ). We conduct further verification to make sure they are genuine members of Sagittarius using parameters such as proper motion, V gsr , and direction of motion. After three steps of verification, we confirm that 10 GCs belong to Sagittarius. Among them, nine have been reported in previous studies, and our verification further confirms their membership in the Sagittarius system. The remaining one, HSC 61, is a newly identified member. Combining these with 21 credible Sagittarius-associated GCs from D. Minniti et al., our final sample includes 31 Sagittarius-associated GCs. Twenty-six are located in the core, and five are located in the stellar stream. We constructed the metallicity distribution in all of Sagittarius; there is one rich peak in the core, and there is one poor peak in the stream. The reason may be that the outer and poorer GCs of the core were first pulled into the stream. Additionally, we analyze the Sagittarius merger event through energy and angular momentum. Elqui is the most distant stream discovered in the Dark Energy Survey at a distance of 50 kpc, and Malhan thought Elqui belongs to the Sagittarius merger. We present new evidence that Sagittarius and Elqui belong to the same accretion event. Through verification, we have added two new star clusters to this large accretion event of Sagittarius. We found that the Large Magellanic Cloud has a certain influence on the orbits of Elqui and Sagittarius.
Funding Information
  • Shandong University (2024YFA1611903)

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