The masses of Milky Way globular clusters using GAIA data

Abstract

Globular clusters are gravitationally bound groups of stars that formed from a common molecular cloud. Globular clusters are, therefore, densely packed and have similar chemical composition, age and kinematics. They have been observed in different galaxy types, thus making them good natural laboratories for studying star formation. Stellar properties within globular clusters provide a reliable means of accurately determining various fundamental parameters associated with these clusters, including distances, ages, metallicities, sizes, and masses. The Leonard-Merritt method is used in this study to measure the masses of the ten closest globular clusters. The mass distribution is modelled by fitting the photometric characteristics of each globular cluster to the King model. The gravitational potential is modelled using the proper motion data from the Gaia space telescope. The precise astrometric measurements from the Gaia mission allow for the most accurate proper motion measurement throughout the galaxy and enable measuring the masses of a vast number of globular clusters using a single data set and one mass measurement technique, providing a perfect point of reference for the Leonard-Merritt technique against the literature masses of this study's chosen globular clusters.