Globular clusters are thought to be the oldest radiant objects in the universe and orbit, usually in large numbers, around galaxies of all morphological types. As fossil remnants of the early environments, out of which galaxies formed, they are powerful probes of the processes of galaxy formation and evolution.

Unlike single stars, globular clusters can be observed far beyond our local group of galaxies, providing clues about the early histories of different types of galaxies. Because they are relatively simple stellar populations (at least chemically), they are more easily modelled and understood than the unknown mix of stars of different ages and chemical compositions that make up the diffuse stellar population of galaxies. 

At the Centre for Astrophysics and Supercomputing (CAS), we are leading the SAGES Legacy Unifying Globulars and Galaxies (SLUGGS) Survey - a wide-field chemo-dynamical survey of early-type galaxies. It capitalises on the unmatched observing power of the Subaru/Suprime-Cam imager and the Keck/DEIMOS spectrograph, combined with state-of-the-art simulations to interpret the observations in a cosmological context. Spectroscopy of the near-infrared calcium triplet provides kinematic and metallicity information for stars (to ~3 effective radii) and globular clusters (to ~10 effective radii) in two dimensions around the survey galaxies.

Unlike single stars, globular clusters can be observed far beyond our local group of galaxies, providing clues about the early histories of different types of galaxies.

The science goals are to map out halo substructure, mass, angular momentum, metallicity gradients, orbital structure and the distribution of dark matter. These fundamental characteristics provide important clues about the assembly histories of galaxies. The survey is a key project of the Study of the Astrophysics of Globular Clusters in Extragalactic Systems (SAGES) network and is supported by the Australian Research Council and National Science Foundation.

At CAS, we are also focused on understanding the complicated internal dynamical evolution of star clusters through simulations performed on the Swinburne supercomputer. The old and massive globular clusters can contain a million stars or more. They represent dense stellar environments which on one hand can produce stellar exotica, e.g. mergers of black holes, through close interactions between stars, but these same interactions can also modify the lifetime and characteristics of the clusters themselves. We aim to investigate and quantify such effects using sophisticated N-body software that models stellar, binary and cluster evolution in parallel.

Our projects

Globular clusters in extragalactic systems

We are investigating the formation and evolution of globular clusters and their host galaxies. This problem is tackled using high resolution imaging from the Hubble Space Telescope, combined with ground-based imaging and multi-object spectroscopy with the Keck telescopes.

Understanding ultra diffuse galaxies 

Using the Keck Observatory and other 8-10m class telescopes, we are investigating a new class of ultra diffuse galaxies that challenge existing theories for galaxy formation. Their globular cluster systems may hold the key to our understanding.

See related research themes

Contact the Centre for Astrophysics and Supercomputing

If you have any questions, or are looking for more information, feel free to contact our office on +61 3 9214 8000 or at

Contact us