Studies of the early Universe with radio telescopes can illuminate the first stars and galaxies that existed, completing our understanding of the evolution of the early cosmos.
M-mode transit interferometry is a novel imaging technique that integrates 24 hours of transit radio interferometer observations into high quality all-sky maps of the large scale Galactic structure. These maps, at low radio frequencies (around 100MHz) are important for radio astronomy because they are used to estimate the sensitivity of instruments. Importantly, these maps are useful for high priority science cases like the Epoch of Reionisation in the first billion years of time, where large scale bright foreground structures are up 100,000 times brighter than the expected 21cm signal from the first stars and galaxies. Accurate all sky models are therefore paramount for correctly calibrating and subtracting these features from real data, having potentially high impact for the detection of the 21cm signal.
Aim
Efforts to map these large scale structures, have been difficult using standard radio interferometry techniques, requiring mosiacking of many snapshot images together, often leading to spatially dependent systematics that affect the usefulness of these maps for foreground calibration, leading to current detection methods relying on foreground mitigation. The m-mode transit interferometry technique requires no mosiacking for large fields of view, and maps the sky structure directly onto the celestial sphere, precluding a lot of the systematics present in traditional methods.
Objectives
Sub-projects:
- Create a software tool for calculating visibilities from a model of the sky and a model of the instrument. Use the model to test the validity of calibration of large scale structure (short spacing baselines) for the MWA, and compare it to the existing method
- Using existing tools, process real MWA and EDA2 data to create new maps, and/or to create spectral models across the EoR bands
- Investigate methods for desourcing mmode maps. Look into the Weiner filtering method (with the correct point source covariance matrix) in the SH-coefficient space for desourcing the map.
Significance
Maps of the large-scale structure of the sky will be crucial for calibrating data from the upcoming SKA telescopes, as well as Curtin University’s existing Murchison Widefield Array. This project will prepare the student for future work with SKA Observatory, or for applications of analysis of complex datasets.
Ideal Candidate
Candidates with interest and capabilities in analysing big datasets, machine learning, and an understanding of radio interferometry would be valuable. Candidates should have a strong grounding in writing scientific software for data analysis, such as Python, use of Jupyter Notebooks.
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.
Internship
Through this project you will also have an internship opportunity. As a CSIRO-affiliated student, there will an opportunity for an internship with CSIRO or SKAO, or an industry partner.
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 Professor Cathryn Trott at Cathryn.Trott@curtin.edu.au
To formally apply submit an Expression of Interest to Professor Cathryn Trott during the Central Scholarship round (July 1st – July 31st 2026)