Research Fellow in Early-Universe Stellar and Galactic Chemical Evolution

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The role

We are seeking an enthusiastic and creative researcher to join a 3-year research project, The Stellar Chemical Blueprint of the Early Universe, led by Dr Robert Izzard at the University of Surrey in collaboration with Professor Chiaki Kobayashi at the University of Hertfordshire, and funded by STFC. Recent observations with the James Webb Space Telescope have revealed very young galaxies whose chemical compositions are unlike those of galaxies in the local Universe. In particular, some high-redshift, low-metallicity galaxies show nitrogen enhanced by around a factor of ten, with carbon also enhanced in some systems. These discoveries pose a major challenge to current models of stellar evolution, nucleosynthesis and galactic chemical evolution. The project asks a fundamental question: which stars made the first chemical elements observed in the earliest galaxies, and how did they do so quickly enough to explain the JWST data?

The successful candidate will work at the interface of stellar evolution, stellar population nucleosynthesis and galactic chemical evolution. The project will develop new models of low- and zero-metallicity stars, including single stars, binary stars, massive stars, very-massive stars and AGB stars. These models will be used to predict chemical yields, especially of carbon, nitrogen and oxygen, and to test whether they can reproduce the abundance patterns observed in early galaxies. The work will make use of and extend the open-source binary_crapid population-synthesis code, including its MINT interpolation framework. It will also connect stellar-population results to one-dimensional and three-dimensional galactic chemical evolution simulations, allowing direct comparison with JWST galaxies and forthcoming survey data from facilities such as DESI, MOONS and PFS. The science goals of the proposal are to:

• identify which stellar sources can produce the unusual nitrogen and carbon abundances observed in early JWST galaxies;
• quantitatively model the chemical yields of low- and zero-metallicity single and binary-star populations;
• test the roles of AGB stars, massive stars, very-massive stars and binary interactions in early chemical enrichment;
• incorporate state-of-the-art stellar yields into galactic chemical evolution models;
• compare model predictions with JWST observations and forthcoming survey data to determine the origin of the elements in the first galaxies.

The role will involve:

• developing new low- and zero-metallicity stellar-evolution grids for use in binary_c;
• modelling the chemical yields of single and binary-star populations across a wide mass range;
• investigating whether AGB, massive, very-massive and binary stars can explain the nitrogen and carbon abundances observed in early galaxies;
• implementing and testing uncertain input physics, including mass loss, nuclear reaction rates and interpolation methods;
• coupling stellar-population results to galactic chemical evolution models;
• comparing model predictions with JWST observations of high-redshift galaxies;
• publishing results in leading journals and presenting the work at national and international meetings;
• contributing to the BRIDGCE collaboration and to the wider research culture of the Astrophysics Group at Surrey.

This is a fixed-term, full-time position for three years, and is planned to start in October 2026.

About you

You will have:

• a PhD, or equivalent research experience, in astrophysics, physics or a closely related discipline;
• experience in computational or data-driven astrophysics;
• programming experience relevant to scientific research;
• the ability to develop, run and interpret quantitative models;
• the ability to communicate research clearly through written work, presentations and collaboration;
• a track record of research outputs appropriate to career stage;
• the ability to work both independently and as part of a collaborative research team.

We recognise that candidates may come from different research backgrounds. You do not need to have worked previously on every aspect of stellar evolution, binary stars and galactic chemical evolution, but you should be motivated to develop expertise across these areas as part of the project.

How to apply

Applications should be submitted online via the University of Surrey jobs portal. Please include:

• a CV, including list of publications;
• a cover letter explaining your interest in the role and how your experience fits the project;
• contact details of at least two referees.

Interviews are expected to take place in June, either in person or online. Informal enquiries are welcome and should be directed to Dr Robert Izzard at r.izzard@surrey.ac.uk.

Further details

Job Description