Study of the motion of Globular Clusters relative to the plane and center of the Galaxy based on Gaia and HST data

TL;DR

This study analyzes the motion of 164 Galactic Globular Clusters using Gaia and HST data to understand their velocities relative to the Galaxy's plane and center, revealing average motion patterns and dependencies.

Contribution

It provides new measurements of globular cluster velocities relative to the Galactic plane and center using combined Gaia, HST, and literature data.

Findings

Average velocities of GCs relative to the Galactic plane were calculated.

GC velocities depend on distance from the Galactic plane.

Average motion of GCs relative to the Galactic center was determined.

Abstract

The authors of the article set out to investigate the motion of Globular Star Clusters (GCs) of the Milky Way relative to the plane and center of the Galaxy. For this study, we used data from 164 Galactic Globular Clusters derived from Gaia, HST, and literature studies. The study calculated the average GC motion velocities relative to the Galactic plane in the northern and southern regions depending on the galactic latitude b and distance from the Galactic plane. The work consisted of using the GC parameters to find the proper motion of clusters along the Galactic latitude b and the velocities V of cluster motion in the perpendicular direction relative to the Galactic plane for the northern and southern regions, respectively, and determine the average values of these velocities. The velocities V of GC motion were also found depending on the distance to the Galaxy plane and their average values were determined. The work also determined the average velocity VR of motion of the GC relative to the center of the galaxy. The study yielded