PhD projects for Astrophysics studies starting in 2026

Supervisor: Sebastian Kamann, Rhys Seeburger

Please note:
This project is only available for full-time, in-person students.

Binary stars play a key role for the evolution of star clusters. Many of the stellar exotica we find in clusters, such as pulsars, blue stragglers, or cataclysmic variables, can only be explained through binary interactions. Binaries also offer us a unique chance to find black holes, and thereby to understand whether star clusters are indeed gravitational wave factories as suggested by theoretical studies. Finally, the binding energies stored in binary stars substantially impact the evolution of their entire host clusters.

In this project, we will explore the interplay between binary stars and their host clusters. Using multi-epoch spectroscopy, which is an invaluable tool in analysing these systems, we will detect and characterise binary stars inside massive star clusters of different ages. The project work will be based on large spectroscopic data sets collected with instruments like MUSE or FLAMES. In addition, we will exploit the upcoming Gaia data release 4 to complete our picture of binary stars in massive clusters.

The questions we aim to answer

What are the period distributions of binaries in clusters of different masses, ages, and densities?

The student will analyse existing MUSE spectroscopic data of Galactic globular clusters and young massive clusters in the Magellanic Clouds. To determine the orbital parameters of the binaries, statistical analysis like Monte Carlo sampling or nested sampling will be used. Where possible, astrometry and photometry from Gaia and the Hubble Space Telescope will be included in the analysis.

How many stars orbit black holes?

Using velocity curves derived from multi-epoch spectroscopy, the student will identify binary systems with unseen, yet massive, companions, like black holes. To distinguish genuine black holes from so-called “black hole imposters” (see below), follow-up

analyses such as spectral disentangling will be performed to determine the nature of the companions.

What are the characteristics of “black hole imposters”?

In our search for black holes we frequently run into imposter systems, binary stars in which interaction between the components has led to unusual stellar characteristics, such as rapid rotation, emission from disks, and overluminous mass donors. These properties make the systems more difficult to analyse, but shed light onto the physics of stellar interaction, which governs the lives and deaths of most massive stars, affecting exciting transient phenomena such as supernovae and gravitational wave mergers. Using multi-epoch spectroscopy, the student will determine their properties and constrain their interaction physics.

Are binaries the reason behind the split main sequences observed in young massive clusters?

A puzzling feature observed in the colour-magnitude diagrams of young massive star clusters are the ubiquitous “split main sequences”, caused by distinct populations of fast and slowly rotating stars. To help answer the question of how these two populations form, the student will use Gaia spectroscopic data to search for a link between the spins and the binary properties of early-type stars.

Supervisor: Ivan Baldry

Please note:
This project is only available for full-time, in-person students.

We can analyse galaxies individually or as a population. Focusing on the latter allows us to empirically track galaxy evolution since, if we measure demographics of galaxy populations at different distances, we are viewing the universe at different epochs. Measurements of galaxy populations can also be compared with cosmological-scale simulations. Galaxy demographics are therefore key for empirically describing and understanding galaxy evolution, and can also play a role in constraining cosmological models.

Some of the key demographic measurements are: the galaxy stellar mass function (distribution of galaxy masses), size-mass relation, colour-mass relation, morphological and dynamical distributions. Related to this are measurements of the properties of the large-scale structure that the galaxies' inhabit: local environment, galaxy groups and clusters. These types of measurements place constraints on the processes affecting galaxy evolution and cosmological-scale models.

Various projects are available in this area, from finding and characterising the lowest-mass galaxies to testing the role of environment on galaxy evolution. New data will be available from the Euclid space telescope, the Rubin Observatory and the 4MOST multi-object spectrograph (in particular, as part of the survey called WAVES).

Supervisor: Renske Smit

Please note:
This project is only available for in-person students (full-time or part-time).

Our understanding of the formation of the first stars, the first galaxies, the first black holes, the first heavy elements and dust particles in the Universe is rapidly changing with revolutionary observational facilities such as the James Webb Space Telescope (JWST) and the Atacama Large Millimetre Array (ALMA).

In this PhD project we will look 13 billion year back in time and measure the physical properties of the first generations of galaxies in order to understand how early galaxy formation takes place.

We will use a multi-wavelength approach by combining (sub)millimetre observations from ALMA (looking at the cold gas and dust) with near-infrared JWST observations (looking at the stars and hot gas within galaxies) to obtain a more complete view of these early systems.

Supervisor: Robert Crain, Jonathan Davies

Please note:
This project is only available for full-time, in-person students.

We are seeking a PhD student to collaborate on the development and analysis of state-of-the-art cosmological simulations of the formation and co-evolution of galaxies and their star cluster populations.

The simulations are based on the COLIBRE galaxy formation model (Schaye et al. 2025), and incorporate sophisticated routines, developed at the ARI, that enable the simulations to incorporate massive globular clusters whose dynamics are modelled self-consistently, as are those of the stellar mass liberated from globular clusters as a result of tidal forces.

The simulations will be used to test theories of the formation of globular clusters (in particular via comparison to JWST observations of distant galaxies), of diffuse stellar haloes, and of the seed population of black holes that grow into supermassive black holes at the centre of galaxies.

Supervisor: Rob Grand

Please note:
This project is only available for full-time, in-person students.

Most of the visible starlight in the Universe emanates from spiral galaxies like the Milky Way, and understanding their formation is a key goal of modern astrophysics. Galaxy properties (such as mass, size, metallicity) depend strongly on how galaxies accrete gas and regulate their star formation: this is driven by many “baryonic” physical processes including black hole feedback (Active galactic nuclei) and the supernovae of massive stars that release large amounts of energy and metals into the interstellar medium, drive galactic winds, and determine the location and rate of star formation over cosmic time.

Cosmological hydrodynamic galaxy simulations are our most powerful theoretical tools to model and constrain this baryonic physics against key galaxy observables, such as galaxy stellar mass.

While recent simulations have achieved much success, there are several outstanding problems, including the unexpected recent finding from the James Webb Space Telescope that revealed spiral galaxies at very high redshift, and observations of bulge-less galaxies (for example disc galaxies with no central, old spheroidal bulge) that no simulation has been able to reproduce. These are major challenges to the currently accepted Lambda Cold Dark Matter cosmogony that require urgent attention.

Progress can only be achieved with a better understanding of how energetic feedback from supernovae and black holes interplays with how galaxies accrete gas and form stellar populations, and constrain them against key galaxy properties like galaxy mass, size, metallicity, and morphology at both early and late times. However, the parameter space of these important physical processes remains poorly explored in cosmological simulations, mainly because a full exploration is computationally too expensive.

In this project, the student will run and analyse state of the art, high resolution cosmological “zoom-in” simulations of the formation of Milky Way-like spiral galaxies from the Big Bang to present day.

They will leverage AI techniques, such as Gaussian process emulators, neural networks and simulation-based inference methods, trained on a large suite of simulations to fully explore the parameter space of the galaxy formation physics (such as feedback, star formation) and map them to a wide range of observable galaxy properties. This will be a powerful way to constrain the physics needed to reproduce observations of both nearby galaxies and high-redshift galaxies.

Some of the key questions we plan to answer are:

• What are the main physical processes governing the masses, sizes, and metallicity of galaxies?
• Can we reproduce bulgeless galaxies within the Lambda Cold Dark Matter paradigm?
• Can we form thin, spiral/barred discs at high-redshift compatible with JWST observations?

The student will join the international Auriga collaboration and have opportunities to work with cutting-edge simulation codes as well as observational data.

Supervisor: Andreea Font

Please note:
This project is available for both in-person and distance learning students, and for both full-time and part-time students.

This project will explore, at unprecedented depth, the predictions of several cosmological models at the scales of individual galaxies, focusing on the properties of faint structures in stellar haloes of galaxies and of low-mass ("dwarf") galaxies.

For this, we will make use a new suite of large volume cosmological simulations constructed in our group, combined with novel machine learning techniques, to probe the properties of galaxies in different dark matter models and different implementations of baryonic physics.

The predictions from these models will be tested against observed properties of galaxies obtained from recent observational surveys, to constrain the nature of dark matter in our Universe and to understand the role that physical processes like stellar feedback and reionisation play at the low-mass end of galaxy formation.

Depending on the interest, the project offers opportunities for running cosmological simulations, developing emulators, or carrying out comparisons with observations.

Supervisor: Ian McCarthy

Please note:
This project is only available for full-time, in-person students.
Line intensity mapping is a new technique for measuring the clustering of matter on large cosmological scales (so-called large-scale structure) using the integrated radio emission from unresolved gas in the Universe. The clustering can be probed as a function of redshift since one knows the rest wavelength of particular lines of interest (for example 21cm line) and can use a radio receiver spanning a wide range of frequencies. Surveys such as CHIME, CHORD, HIRAX, MeerKAT, and the Square Kilometre Array (SKA) will soon use line intensity mapping to measure the matter power spectra of density fluctuations all the way back to the epoch of reionisation. In this study, the student will use brand-new simulations developed in-house at ARI to make predictions of the 21cm signal for these surveys. The simulations explore variations in dark matter, dark energy, massive neutrinos, models of inflation, as well as the physics of galaxy formation. The student will develop machine learning models that map the observed 21cm signal back to the cosmology and galaxy formation physics in order to provide crucially important interpretation of the forthcoming data.

Supervisor: Ian McCarthy

Please note:
This project is only available for full-time, in-person students.

Fast Radio Bursts (FRBs) are powerful, millisecond-long flashes of radio waves emitted from energetic transient objects such as magnetars. As this radio emission traverses the Universe it interacts with free electrons causing lower frequency photons to arrive later relative to high frequency photons.

This so-called dispersion measure provides a direct measure of the column density of free electrons along the line of sight to the FRB. With a sample of many FRBs spanning different redshifts, we can build a 3D mapping of the distribution of ionised gas in the Universe.

In this project, the student will use cosmological hydrodynamical simulations that vary nature and strength of cosmic feedback from supernovae and supermassive black holes (which blows hot ionised gas out of galaxies) to make predictions for forthcoming FRB surveys which promise to place strong constraints on feedback.

These results will also be incredibly valuable to cosmological studies of large-scale structure (for example, cosmic shear) where the predictions depend sensitively on the modelling of feedback.

Supervisor: Paolo Mazzali

Please note:
This project is available for both in-person and distance learning students, and for both full-time and part-time students.

Supernovae are arguably one of the most interesting astrophysical events. They are among the most luminous object in the Universe. They mark the end of the lives of different types of stars, enrich the interstellar medium with nuclearly processed elements, are essential for cosmology as distance indicators, and are linked with extremely powerful events such as gamma-ray bursts.

Students can work on a variety of topics, including observations, interpretation of the data, modelling spectra and light curves as well as developing new and more advanced codes.

Projects will be discussed and defined on an individual basis, such as to achieve the best match between the interests, abilities and situation of the student on the one hand and current research topics on the other, and thus can be either full- or part-time.

Possible topics include Type Ia SNe (physics and use as standardizable candles), stripped-envelope (Type Ib/c) SNe (physics and connection with Gamma-ray bursts), Superluminous SNe (physical processes).

Supervisor: Daniel Perley

Please note:
This project is only available for full-time, in-person students.

It has been known since the mid-20th century that some massive stars shed most or all of their hydrogen prior to explosion, resulting in Type Ib and Ic supernovae (and a variety of other subtypes identified somewhat more recently: IIb, Ibn, Icn, and SLSN-I).

But it is still not fully understood how or why this happens: for example, is the hydrogen lost in winds, is it stripped by a binary companion, is it ejected during a merger, or some combination of all of these effects? At the time of birth, were the progenitor stars of these supernovae more massive or less massive than those responsible for other types of CCSN?

This project will address what can be learned about these systems from a data-driven perspective using large samples of light curves and spectra from the Zwicky Transient Facility, the world's largest supernova survey to date.

Current data suggest that in addition to the known spectroscopic classes, there are multiple distinct, previously-unrecognized photometric subgroups that may point to distinct progenitor channels.

This project would use a combination of existing and new data from ZTF, the Liverpool Telescope, and the newly-commissioned Rubin Observatory to pursue this hypothesis further and provide new insights into the evolution and deaths of massive stars.

Supervisor: Matt Darnley, Daniel Harman, Fiona Murphy-Glaysher

Please note:
This project is available for both in-person and distance learning students, and for both full-time and part-time students.

Classical and recurrent novae are among the Universe’s most energetic stellar explosions—surpassed in brightness only by supernovae and gamma-ray bursts. Unlike these rarer events, novae occur frequently: large galaxies such as the Milky Way or Andromeda can host more than 50 eruptions every year. Their abundance and luminosity make them exceptional laboratories for studying extreme astrophysics on human timescales.

Over the past decade, novae have emerged as key contributors to Galactic chemical evolution, producing isotopes such as carbon-13, nitrogen-15, oxygen-17, and lithium. Recent work (For example, Hillman et al. 2016; Darnley et al. 2019) has further strengthened the case for novae as a viable single-degenerate pathway to Type Ia supernovae—one of the most important open questions in modern astrophysics.

The Nova Group at the Astrophysics Research Institute (ARI) has been a leading centre for nova research since 1992. Our team combines expertise in rapid multi-wavelength observations (optical, UV, X-ray), extragalactic transient surveys, and multi-dimensional hydrodynamical simulations. We work closely with international collaborators and have access to a broad range of observational facilities and LJMU’s high-performance computing resources.

We offer PhD projects spanning the full range of nova science—from observational campaigns and survey-driven population studies to theoretical and computational modelling. Students will develop skills in data analysis, numerical simulation, instrumentation, and scientific communication while contributing to an active and supportive research environment.

Current areas of research include:

• formation and evolution of nova super-remnants
• panchromatic observational campaigns targeting rapid recurrent novae
• population studies of extragalactic novae in nearby galaxies
• multi-dimensional hydrodynamical simulations of nova ejecta and shock interactions

Supervisor: Chris Copperwheat

Please note:
This project is available for both in-person and distance learning students, but not for part-time students.

The Legacy Survey of Space and Time (LSST) conducted by the Vera C. Rubin Observatory is set to revolutionise transient science, discovering millions of events per night by monitoring the variable sky at unprecedented depths and cadences.

It will identify tens of thousands of new cataclysmic variables (CVs) — interacting binary systems in which a white dwarf accretes matter from a companion star via their variability.

This project will focus on time-domain photometry and spectroscopy to characterise the accretion dynamics, orbital parameters, and outburst behaviour of these systems. It will build on existing work done at the ARI to develop a machine learning classification approach1 for cataclysmic variable stars which has been successfully applied to the Gaia Alerts and ZTF surveys.

We will use the Liverpool Telescope and other facilities to follow up, classify and characterise the candidates we identify in the survey, contributing to our understanding of accretion physics, binary evolution, and population demographics of CVs across the Galaxy.

The student will gain expertise in time-domain astronomy, robotic telescope operations, and data-driven astrophysical modelling.

Supervisor: Iain Steele, Helen Jermak

Please note:
This project is only available for full-time, in-person students.

Gamma-ray bursts are some of the most energetic transient events in the universe, they are powered by relativistic jets produced by neutron star mergers and the collapse of massive stars. Although the acceleration and collimation processes of GRB jets (and other relativistic jets from compact objects) are still open questions, recent observations imply the importance of magnetic acceleration processes (for example the magnetic field around the compact object becomes twisted and amplified by the rotation and the magnetic pressure accelerates the jet).

According to the magnetic models, the magnetic field in the jet is expected to be well ordered, while alternative models predict random magnetic fields or a patchwork of unaligned magnetic regions. Since photons are produced by the synchrotron process, they are polarised perpendicular to the magnetic field lines in each fluid element of the emission region.

The net polarisation signals depend on the geometry and relativistic effects. Polarimetry offers a unique probe of the physical conditions and geometry of the jets, and gives constraints on the jet acceleration process and plasma physics in a relativistic regime.

The Liverpool Telescope has made most of the (still relatively few) successful measurements of early-time optical GRB afterglow polarisation through the RINGO series of polarimeters. These instruments' unique capability was to measure polarisation on very short timescales for poorly localised sources. We have now built a new polarimeter (MOPTOP) which has ~4 times the sensitivity of RINGO.

This will allow us, in only 3 years, to double the sample size of GRB polarisation measurements. This will make it possible, for the first time, to start to disentangle correlations between the observed polarisation and derived jet properties over a representative sample of bursts. In addition the low systematic errors of MOPTOP will mean that for the first time we will be able to constrain behaviour at low polarisation.

In this regime the turbulent patch model is expected to operate and we will test the prediction that this model will give polarisation angle variability, as opposed to the constant orientation we observe in the highly polarised and therefore magnetically collimated bursts.

The PhD student will lead the collection and analysis of the GRB data, working within a wider collaboration incorporating staff from LJMU as well as the universities of Ferrara (Italy) and Nona Goricia (Slovenia) who will provide expert advice and support on the theoretical interpretation of the data.

If time allows, we will also extend the project to the analysis of a wider sample of transient sources, exploring the possibility of using polarimetry as a more efficient classification tool than spectroscopy for the deluge of transients expected from VRO/LSST.

The following three papers provide some more information about GRB polarimetry and MOPTOP:

• Polarimetry and Photometry of Gamma-Ray Bursts with RINGO2
• Characterization of a dual-beam, dual-camera optical imaging polarimeter
• Polarimetry and photometry of gamma-ray bursts afterglows with RINGO3