Milky Way and Local Group

Understanding the Galaxy and its neighbours

Our location in the Milky Way provides us with a unique vantage point to study the structure, composition and kinematics of our home galaxy, the Andromeda galaxy and other galaxies in our Local Group.

Our researchers participate in a range of surveys, including:

• 4MOST
• GALAH
• the Legacy Survey of Space and Time
• the Southern Stellar Stream Spectroscopic Survey (S⁵)
• the VISTA Survey of the Magellanic Clouds

We make extensive use of telescopes at home and abroad, including the Very Large Telescope and the Vera Rubin Observatory.

Learn more about the projects we are undertaking, the researchers engaged in them and who you can contact to get involved.

Forming the Milky Way inside out

Star formation in galaxies proceeds in a complex, hierarchical fashion, shaped by turbulence, gravity and stellar feedback, yet the dominant modes of star formation in our own Milky Way remain poorly characterised.

This PhD project will exploit the unprecedented astrometric precision and all-sky coverage of Gaia to identify and analyse clustered young stellar populations across the Galactic disc, from compact embedded groups to extended star-forming complexes.

By applying modern clustering and statistical techniques to large Gaia samples, the project will quantify the spatial hierarchy, characteristic scales and environmental dependence of star formation in the Milky Way and directly compare these properties with those observed in nearby galaxies.

The results will provide new insight into whether star formation operates through universal, turbulence-dominated processes or whether distinct modes emerge in different Galactic environments, linking local star-forming regions to galaxy-scale star-formation physics.

Galactic archaeology

Galactic archaeology – the detailed study of stars in our galaxy and its nearest neighbours in order to uncover clues to their formation and evolution – is entering a new era with the availability of detailed elemental abundances and precision radial velocities for over a million stars in the Milky Way from the GALAH (GALactic Archaeology with HERMES) survey.

Combining GALAH with data from the ESA space mission, Gaia will open new frontiers in our understanding of the formation and evolution of the galaxy.

In this project, you will work with members of the GALAH team and other international collaborators.

To get involved in this project, contact: Daniel Zucker

Modes of star formation across the Milky Way

This PhD project explores how stars form across the Milky Way and seeks to understand whether star formation occurs primarily in isolated environments or through a complex hierarchical process.

Recent research increasingly supports the idea that stars form within nested structures: Large, diffuse stellar groupings contain smaller and denser subgroups, which themselves fragment into even more compact structures. These hierarchical patterns are believed to originate from the fractal nature of the interstellar medium (ISM), where gas and dust are organised into clouds, clumps and cores across a wide range of scales.

The project will investigate the physical mechanisms driving this hierarchical star formation. In particular, it will examine the roles of turbulence, gravity, stellar feedback and other environmental processes in shaping stellar structures. Supersonic turbulence is thought to fragment molecular clouds and regulate star formation on both large and small spatial scales, while energetic events such as stellar winds and supernovae further influence the ISM.

A major strength of the project is its use of the highly precise astrometric and photometric data from the European Space Agency’s Gaia mission Data Release 3 (DR3), which contains thousands of reliably identified stellar clusters across the galaxy. Using advanced techniques such as contour-based clustering and dendrogram analysis, the student will identify and characterise hierarchical stellar structures throughout the Galactic disk and spiral arms.

The research will address three key scientific questions:

• how star-formation duration depends on the size of a region
• what physical mechanisms, beyond turbulence and gravity, govern star formation
• when and why stellar complexes disperse into the Galactic disk.

By combining large-scale observational datasets with modern statistical analysis, the project aims to provide new insights into the fundamental processes controlling the birth and evolution of stars in our galaxy.

To get involved in this project, contact: Richard de Grijs

Satellites and stellar streams in the Local Group

Galaxies like our Milky Way form by accreting smaller systems and this process of galaxy cannibalism continues to the present day. The dwarf satellites orbiting the Galaxy and M31 – its nearest large neighbour – are survivors, while the victims are stretched across the sky in stellar streams.

These satellites and streams, many of them revealed by wide-area astronomical surveys, probe the conditions of galaxy formation in the early universe and the behaviour of dark matter on the smallest scales.

In this research area you will have the opportunity to work with collaborators at other universities in Australia and overseas.

To get involved in this project, contact: Daniel Zucker

Stellar variability: Redefining the Milky Way’s fundamentals

We will exploit the most extensive and statistically complete catalogue of 572,338 periodic variable stars in the Milky Way to robustly quantify our galaxy’s 3D mass/stellar distribution.

We will conclusively determine the time evolution of the Milky Way’s spiral arms and of its warped stellar disk to distances two to three times further from the galaxy’s centre than our Sun. Accurately knowing the Milky Way’s structure is fundamental, since it is the benchmark by which we measure external galaxies.

The research project will also set the standard for stellar structure studies and analyses of gravitational-wave source properties.

To get involved in this project, contact: Richard de Grijs