Studying the gas and dust between the stars

Research projects in this area study the detailed physics of the interstellar medium (ISM), to understand how it has evolved in our Milky Way and nearby galaxies, and how it impacts star formation in the Universe.

Our researchers use varied techniques – from radio, optical and infra-red observations, to numerical models and analytical theory.

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

Revealing dust properties in distant environments

Cosmic dust plays a crucial role in the formation of galaxies. Measuring dust extinction at different wavelengths reveals information about dust grain sizes, compositions and properties.

Our detailed knowledge of dust is limited to local calibrators like our own Milky Way, which limits the accuracy of deriving properties for high-redshift objects like quasars and gamma-ray bursts.

This project will use multi-wavelength spectroscopic and photometric observations from various telescopes (including ESO VLT) for these high-redshift objects to generate their spectral energy distributions and hence derive individual extinction curves rather than using reference Local Group extinction laws.

Supervisor: Tayyaba Zafar

Mapping ‘dark’ molecular gas with SPLASH

Molecular hydrogen (H2) exists in vast clouds throughout the Milky Way, but the molecules themselves produce no observable emission.
Astronomers therefore use emission from carbon monoxide (CO) to trace molecular gas. However, in more diffuse environments, CO splits back into its constituent atoms, leaving vast clouds of ‘invisible’ H2.

In this project you will work with data from SPLASH – the Southern Parkes Large-Area Survey in Hydroxyl – to reconstruct the 3D distribution of hidden molecular gas in the Milky Way, and measure how much of the Milky Way’s molecular gas is hiding in plain sight.

Supervisor: Joanne Dawson

The Australia Square Kilometre Array Pathfinder as a hydroxyl absorption machine

The Australia Square Kilometre Array Pathfinder (ASKAP) comprises 36 linked radio dishes in the desert of Western Australia. ASKAP is pioneering new radio telescope technologies, driving some of the fastest and deepest surveys of the radio sky.

In this project you will lead the analysis of the first OH absorption data from the GASKAP-OH survey, which is producing the widest and most sensitive interferometric survey of OH ever undertaken.

You will lead the first science, optimise data reduction strategies, and work together with the GASKAP-OH team to drive publication of the first OH science results from the ASKAP telescope.

Supervisor: Joanne Dawson

Huntsman Probes the Cosmic Web – characterising the foreground galactic circus

Like cirrus clouds obscuring the sky from the Earth’s surface, Galactic cirrus are vast clouds of interstellar gas and dust in our own Milky Way that absorb light from background galaxies.

While these clouds present challenges to astronomers aiming to image the distant universe, they also present an opportunity to study the local interstellar medium in unprecedented detail.

This project uses the new Macquarie University Huntsman Telescope to image ultra-faint Galactic cirrus. You will develop image-processing techniques to disentangle this foreground structure from background galaxies and ultimately study the properties of turbulence in the interstellar medium.

Supervisors: Lee Spitler and Joanne Dawson