Cosmology and Reionisation

Our projects

Ionisation and metals 

We are investigating how Lyman-continuum photons escape from star-forming regions and into the intergalactic medium, and how metals escape galaxies, especially in the early universe. 

For more information, contact Associate Professor Emma Ryan-Weber.

Fundamental constants in distant galaxies 

Using quasars as powerful background beacons, we are searching for cosmological variations in the fundamental constants of nature by studying gas in the outskirts of distant galaxies with the world's best telescopes.

Weighing the universe with deuterium 

This project aims to weigh the universe by comparing the amount of hydrogen and its main isotope, deuterium, in distant, almost pristine clouds of gas.

The Taipan galaxy survey 

Taipan is a new spectroscopic survey facility at Siding Spring Observatory that has been designed to measure the distances to millions of galaxies across the entire Southern sky in order to construct a comprehensive map of the properties, structure and motion of galaxies in the nearby universe.

The Dark Energy Spectroscopic Instrument (DESI)

We are participating in DESI, a new US-based observational facility that will obtain optical spectra for tens of millions of galaxies, measuring the effect of dark energy on the universe.

The universe's first billion years 

Using the next generation James Webb Space Telescope and new machine learning methods, we aim to find rare and unusual galaxies and stars that emerged in the first billion years of cosmic history.

We are using national and international facilities to construct new maps of the local and distant universe at optical and radio wavelengths.

Galaxy and mass assembly

By combining distance measurements from optical spectroscopy with panchromatic imaging spanning X-ray, ultraviolet, optical, near-to-far infrared, and radio wavelengths, census-class galaxy surveys like GAMA, DEVILS, and WAVES provide a comprehensive view of the astrophysical processes that shape the lives of galaxies.

Measuring the masses of galaxies 

We are pioneering new experimental approaches to measure the total mass of the dark matter halos that surround galaxies through the relativistic effect of weak gravitational lensing. By connecting the properties of galaxies to the total mass of their larger dark matter halos, the goal is to derive new insights into how the dark matter influences the formation and evolution of galaxies. 

Fundamental physics with solar twin stars 

Do the fundamental constants of nature vary, and are they deeply connected to mysterious phenomena like dark matter? We are testing fundamental physics by discovering, and precisely measuring the spectra of distant stars almost identical to our sun, to map the strength of electromagnetism across our galaxy in regions of very different dark matter.

UVES SQUAD: The UVES Spectral Quasar Absorption Database 

UVES SQUAD is the largest set of high-resolution quasar spectra, built from the data archives of the UVES instrument on the 8-metre Very Large Telescope, and has contributed to a wide array of cosmology, quasar and circumgalactic/intergalactic medium studies so far.

Discovering remnants of the first stars 

Within spectra of distant quasars from the world's best optical telescopes, we are discovering rare, almost pristine gas clouds that may have been enriched with the metallic debris from the explosions of the universe's first stars.

Lyman continuum galaxies - uncovering the sources of reionisation 

This project uses the Hubble Space Telescope, Keck Telescope, and other deep imaging and spectroscopy to uncover the sources responsible for the Epoch of Reionisation (EoR) and understand their physics and mechanisms of ionising flux escape.