Internal dynamics of globular clusters

Internal Motions in Globular Clusters

Observations of internal motions in globular clusters offer unique insights into the dynamics of the clusters. We have recently developed methods of high-precision astrometry with HST 's WFPC2 camera, which allow us to measure internal proper motions of individual stars. These new data open up many new avenues for study of the clusters. Comparison of the dispersion of proper motion with that of...

Accurate Internal Proper Motions of Globular Clusters

We have undertaken a long term program to measure high precision proper motions of nearby Galactic globular cluster (GC) stars using multi-epoch observations with the WFPC2 and the ACS cameras on-board the Hubble Space Telescope. The proper motions are used to study the internal cluster kinematics, and to obtain accurate cluster distances. In this paper, we also show how the proper motions of t...

Dynamics of Stars and Globular Clusters in M 87

We examine the dynamics of the stars and globular clusters in the nearby giant galaxy M87 and constrain the mass distribution, using all the available data over a large range of radii, including higher-order moments of the stellar line-of-sight velocity distributions and the discrete velocities of over two hundred globular clusters. We introduce an extension of the spherical orbit modeling meth...

Mergers of Globular Clusters

Dissolution of Globular Clusters

Globular clusters are among the oldest objects in galaxies, and understanding the details of their formation and evolution can bring valuable insight into the early history of galaxies. Until the late 1970s, globular clusters were thought of to be relatively static stellar systems, a view which was supported by the fact that most observed density profiles of globular clusters can be fitted with...