Fast radio bursts (FRBs) are millisecond-duration extragalactic transient events, so powerful that they can be detected after travelling more than half the age of the Universe to reach Earth. Currently, the origin of FRBs is unknown, although lead theories include young, rapidly rotating, and highly magnetised neutron stars; and the merger of compact objects such as a neutron star and a white dwarf. Critically, the frequency dependent time-delay induced as an FRB passes through ionised gas measures the total column density of that gas. Known as the ‘dispersion measure’ (DM), this delay allows FRBs to be used as probes of the structure of matter in the Universe.
The ‘CRAFT’ Collaboration uses the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope to detect FRBs, determine their direction of origin, and study the properties of their emission down to nanosecond timescales. Our science has been awarded the 2020 Newcomb Cleveland Prize for most impactful Science paper that year, and we have published four other articles in Nature and Science magazines. To interpret FRB data, we have developed the “zDM” code, allowing studies of the cosmological evolution of the FRB population, the fraction that repeat, and their energy distribution; and also the distribution of matter in the Universe, and to independently determine cosmological parameters.
Aim
The aim of this project is to use a world-leading code title “zDM” to model FRB data from international experiments such as CHIME, DSA, FAST, and MeerTRAP as well as ASKAP to determine the detailed structure of matter in the Universe. Specific questions include: how much matter exists in the circum-galactic medium vs the intergalactic medium? What is the evolution of ionised gas around FRB host galaxies? What is the intrinsic distribution of FRB host galaxies, and how does FRB repetition bias our observations of it? Do FRBs trace star-formation, or is there a delay before FRBs become active? The project will be conducted in concert with the CRAFT Collaboration, which is centred on Perth, Melbourne, and Sydney, but has extensive international collaborators in Chile, the USA, Germany, and Japan. Collaboration with galaxy evolution and cosmology experts at the University of WA is also possible.
Objectives
The objectives of this project will be to develop the zDM codebase and use it to model FRB data. zDM, written in Python, is the world-leading software for modelling FRBs. It accounts for experimental bias effects, cosmological gas distributions, and the intrinsic properties of the FRB population. Specific objectives for improvement are allowing for the non-Poissonian rate of FRB repetition, improving models of FRB scattering and spectral dependence, and allowing for redshift-dependence in host galaxy properties and variance in DM due to the CGM and IGM. This will allow an ever-more accurate interpretation of FRB data, and will answer questions as diverse as “Do FRBs come from one or two populations?”, “What is the rate of expansion of the Universe?”, and “How do Galactic feedback processes affect the ionised gas distribution in Galaxy halos?”.
The successful candidate should also expect to work with the cosmological theory and galaxy evolution groups at the University of Western Australia ICRAR node, and the F4 (Fast and Fortunate FRB Followup) Collaboration in the US.
Significance
Fast radio bursts were only confirmed to exist in 2013. They are the brightest radio transients in the Universe – so bright, that they can be seen from over eight billion years ago, when the Universe was less than half its current age. The physical processes which produce them are therefore probes of extreme physical environments, such as the most highly magnetised, rapidly spinning neutron stars, at the theoretical limits of electromagnetic field strengths. By measuring the column density of ionised gas, FRBs also have the ability to probe the structure of the Universe, promise to resolve the current Hubble tension, and detect the otherwise invisible hot gas surrounding galaxies. This dual promise of probing extremes of both large-scale and small-scale physics makes FRBs one of the hottest current topics in astronomy – and the zDM code is the only one which can model key biases and correctly interpret FRB observations.
As part of the International Centre of Radio Astronomy Research (ICRAR), the Curtin Institute of Radio Astronomy founded the CRAFT project to detect FRBs with ASKAP back in 2008, and in 2020, Curtin’s A/Prof Jean-Pierre Macquart established the redshift-DM relation now known as the Macquart relation in his honour. This project places the student at the forefront of this dynamic field, and gives them the opportunity to advance it to even greater heights.
Ideal Candidate
We are looking for a self-motivated PhD applicant who is interested in problem-solving, not afraid to tackle technically complex problems, and with a background in quantitative sciences (an astronomical background is preferred but not required).
Additionally, the applicants should meet the eligibility criteria for entry into a PhD program at Curtin University.
This project is open to Domestic applicants only.
Scholarship
If you are identified as the preferred candidate for this project, you may be considered for an RTP scholarship.
Enquires and How to Apply
For enquires about this opportunity contact Associate Professor Clancy James at Clancy.James@curtin.edu.au
To formally apply submit an Expression of Interest to Associate Professor Clancy James during the Central Scholarship round (July 1st – July 31st 2026)