Kinematics of Multiple Stellar Populations in Globular Clusters with Gaia

TL;DR

This study investigates the internal kinematics of multiple stellar populations in six globular clusters using Gaia data, revealing rotation patterns and differences among populations that inform cluster formation theories.

Contribution

It extends previous kinematic analysis to six globular clusters, highlighting rotation features and population differences with Gaia data, advancing understanding of cluster dynamics.

Findings

NGC0104 and NGC5904 show significant rotation.

Different stellar populations in NGC5904 have distinct rotation curves.

Analysis of six clusters expands knowledge of globular cluster kinematics.

Abstract

The internal dynamics of multiple stellar populations in Globular Clusters (GCs) provides unique constraints on the physical processes responsible for their formation. Specifically, the present-day kinematics of cluster stars, such as rotation and velocity dispersion, seems to be related to the initial configuration of the system. In recent work (Milone et al. 2018), we analyzed for the first time the kinematics of the different stellar populations in NGC0104 (47Tucanae) over a large field of view, exploiting the Gaia Data Release 2 proper motions combined with multi-band ground-based photometry. In this paper, based on the work by Cordoni et al. (2019), we extend this analysis to six GCs, namely NGC0288, NGC5904 (M5), NGC6121 (M4), NGC6752, NGC6838 (M71) and further explore NGC0104. Among the analyzed clusters only NGC0104 and NGC5904 show significant rotation on the plane of the sky. Interestingly, multiple stellar populations in NGC5904 exhibit different rotation curves.