Southampton Astronomy: 2025 projects available now!

Compact Objects, Time Domain Astronomy, Space Physics and Exoplanets

Postgraduate Studies in Southampton: we have new projects for 2025

The School of Physics and Astronomy at the University of Southampton offers postgraduate studies (Ph.D.) in a variety of fields in astronomy, space science and planetary sciences.

Possible research topics are generally outlined by the research interests of our members of staff. If you have any questions about any particular topic you are welcome to contact staff members directly.

Have a look at the astronomy group's home page to find out more on what we do here. More general information on postgraduate work in the Physics and Astronomy department at Southampton is available. For more information about the University and its surroundings, look at the University home page.

At the University of Southampton, we value diversity and equality. Both the University of Southampton and the School of Physics and Astronomy are proud to hold Athena Swan Silver Awards. To find out more about our commitment to Equity, Diversity and Inclusion see here.

Research Projects for PhDs starting in Sep-Oct 2025

Several PhD places will be available in the astrophysics group this year, with projects chosen from among those listed below. Candidates may express a preference for project/supervisor (or several projects/supervisors) in their application but this is not mandatory. Review and ranking of applications will start on January 17th 2025, and successful candidates will be invited for online interviews shortly after. Late applications may be considered if funding is available but please apply by January 17th for the best chance to be selected.

Scroll down to view the PhD projects available this year

Contact

For further information, please contact:

Dr. Sandra Raimundo
PGR Admissions Tutor for Astronomy

Room 4063 (building B46); School of Physics & Astronomy
University of Southampton
Highfield, Southampton
SO17 1BJ, U.K.

Email: s.raimundo@soton.ac.uk

How to apply

To apply you will need to get an application form (which asks brief details of your past courses) and the names and addresses of two people who can provide you with a reference (you do not need to upload references yourself, the system will automatically send out a request to the contacts you have provided). The key aspects are (a) what degree course you have done (and relevant transcripts); (b) a research statement to highlight any relevant components, especially project/research work, motivation, skills and scientific interests, (c) your CV and (d) your references. You do not need to provide a separate research proposal as all the relevant information should be contained in the 'Personal Statement' section. In case you are planning to apply for external funding, please add that information to your application under the 'Funding' section. All students will be considered for our internal scholarships, if eligible.

If you are interested in applying and would like an application form and further information, please fill in the on-line form, apply to the "PhD Physics" programme (you have to search for PhD Physics, with Programme:Research and in the 2025-2026 academic year -- you can alternatively apply for PhD Physics & Astronomy Mayflower - you do not need to submit multiple applications). If requested, please specify "Astrophysics" in the "Topic of field or research" section to have your application directed to the astronomy group.
To download the application guide, please click here.

For more information on how to apply please visit the University web page.

Training
Research Facilities
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Uncovering 12 billion years of supermassive black hole growth  

One of the most consequential discoveries in galaxy evolution was the discovery that the masses of supermassive black holes (SMBHs) in the centres of galaxies are correlated with properties of the host galaxy. Understanding this link and how both components evolve together requires accurate measurements of SMBH masses across cosmic time. However, beyond the local universe (redshift z > 0.2), we currently rely on indirect methods that are prone to systematic uncertainties and may give the wrong impression of how fast SMBHs grew in the early universe. 
 
SMBH FACTORY is a new 5-year project selected through the ERC Advanced Grant and funded through the UKRI Horizon Guarantee. With SMBH FACTORY, we will use the revolutionising angular resolution of infrared interferometry (GRAVITY+), the most sensitive industrial-scale reverberation mapping campaign (TiDES-RM), and novel 3D radiation hydro-dynamic simulations to measure “gold standard” SMBH masses out to redshift z ~ 3. We will answer the questions of how SMBHs grew through cosmic time and how they interacted with the growth of their galaxies.
 
As part of the PhD project, you will contribute at the critical interlink between observations and mass measurements. You will develop an advanced time-resolved spectral decomposition pipeline for the 4MOST TiDES reverberation mapping campaign, recover emission line lags of multiple lines, and determine black hole masses from 2 billion years after the Big Bang to today. You will be supported by the SMBH FACTORY team members, learn a wide variety of observational and modelling techniques and be exploiting data from the largest photometric and spectroscopic surveys, including LSST and 4MOST. We are working with international collaborators in Europe, the US, and Australia on this project and you can expect opportunities for research visits. 
 
When applying to this position, please highlight what excites you about this project and what skills you can contribute to the team.
 


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Exploring the Extreme Venus Climate and Hot Terrestrial Exoplanets

Dr. João M. Mendonça invites applications for a 4-year PhD research position in computational modelling of planetary climates. The successful applicant will join the new research group in planetary sciences at the University of Southampton. Thanks to the successful Horizon Europe Guarantee grant , the group will soon grow to 8 members.
 
Project description:
 
Simulating the Venus climate has been a challenge for the scientific community for over four decades. Venus, the planet in the Solar System most similar to Earth in terms of mass and size, has a massive CO2 atmosphere that creates extremely harsh conditions on its surface. The planet is completely covered by clouds containing a mixture of sulphuric acid and water droplets. Venus's unique conditions provide an opportunity to test our computational models under extreme circumstances. Venus's atmospheric circulation exhibits poorly understood physical dynamic features, such as super-rotation, where the atmosphere rotates much faster than the solid planet, and the rapidly changing polar vortex. Understanding the physics behind Venus's climate is crucial for characterizing the climate of potential exoplanets similar to Venus.
 
The student will use a cutting-edge computational model of planetary climates (OASIS) to create 3D simulations of Venus and Venus-like atmospheres that go beyond the current state of the art. The student will have access to high-performance computing facilities at Southampton, opportunities to engage in international collaborations, visits to other research groups abroad, and to acquire new skills in modern high-performance computing techniques for simulating the fundamental physics of planetary climates.
 
In this project, the student will: a) Investigate the role of clouds in driving observed dynamical features in the atmosphere, such as super-rotation and polar vortex; b) Analyze results from simulations with unprecedently high spatial resolution; c) Explore 3D simulations of exoplanets with astronomical parameters resembling Venus conditions and develop tools for characterizing the atmosphere of these planets using observations from the James Webb Space Telescope.  
 

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Finding the unexpected in vast pulsar data sets

A PhD position is an opportunity to direct your enthusiasm and creativity into ground-breaking research, with support to develop the skills you need to become a leader in your field. In this project, you will push the boundaries of our understanding of extreme neutron star physics, developing your own research ideas and building expertise in AI and large-scale data science. You will apply machine-learning and data science techniques to discover anomalies in vast data sets of radio pulsar observations, and use these to understand how neutron stars evolve over their lifetimes.
 
Pulsars, spinning neutron stars emitting a beam of radio waves, are some of the most extreme objects in the Universe, yet the physics of how they are powered remains a mystery. The best chance of advancing understanding is to find ordinary pulsars behaving in unexpected ways. In this project, you will use over a million radio pulses from a thousand pulsars observed with MeerKAT, the most sensitive radio telescope in the Southern hemisphere. With so many observations to study, we need to take an AI-centred approach to handle the influx of information. You will apply novel visualizations, statistics and unsupervised machine-learning to discover the cases where pulsars behave strangely, and work with an international team of experts to investigate the causes of this behaviour. You will then use these discoveries to make connections across the radio transient population, from incredibly fast-spinning millisecond pulsars, to extragalactic Fast Radio Bursts.
 
What opportunities and support can you expect?
 
• The opportunity to take ownership of your research and become a leader of projects and publications.
  • A schedule of weekly supervisor meetings to help guide your development.
  • Membership of international collaborations with two of the world’s best radio telescopes: Murriyang and MeerKAT.
  • The chance to work with experts from across the world, particularly the UK, Germany, South Africa and Australia.
  • A network of mentors both within pulsar science and at the University of Southampton.
  • Training: in data science and machine-learning; in Python programming and software development; in managing very large data sets; and in key communication skills.
  • Opportunities to present your research at national and international conferences.
  • A collaborative research trip to Australia.
 
Click here if you would like to learn more, and please feel free to contact me with any questions!

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Uncovering extremely luminous flares from supermassive black holes with next-generation survey telescopes

Modern all-sky astronomical surveys have started picking up unusual, extremely luminous, and long-lived flares in the centres of distant galaxies. They are too bright to be caused by the death of a single star and are more likely a violent accretion of material onto a supermassive black hole. The focus of this PhD project is to unveil what that material is and how it gets, which is key to understanding how black holes grow. 
 
So far, roughly 20 of these ambiguous nuclear transients (ANTs) are known, including the most energetic cosmic event ever observed which was discovered by the Southampton group. Some seem to occur in galaxies that have a black hole that is already accreting material (an “active galactic nucleus”; AGN) while others have no sign of activity. One explanation is that a massive star, several times the size of the sun, gets shredded by tidal forces from the black hole - but how and why the star gets there is difficult to explain. On the other hand, the timescales of these events are far too short to be caused by large-scale instabilities in existing accretion disks. Finally, most of the events have “echoes” seen at mid-infrared wavelengths, implying that they are shrouded in warm dust: perhaps some of this dust is what is falling into the black hole. To answer these mysteries, this project make use of the Southampton group’s leading position in two of the most exciting new telescopes in the world: the Vera Rubin Observatory and its Legacy Survey of Space and Time (LSST) will discover millions of new astrophysical transients like supernovae, tidal disruptions of stars, and hundreds or thousands of ANTs, dwarfing any previous survey by orders of magnitude.
 
Southampton is a core member of the TiDES survey which will obtain a spectrum of every ANT discovered by LSST. In this project you will compare state-of-the-art theoretical models with the LSST light curves and TiDES spectra to measure the energy, the black hole mass, and the chemical composition of these mysterious flares. You will also have the opportunity to use other world-class facilities such as the Very Large Telescope and the James Webb Space Telescope. You will work in an international research team with great opportunities for travel and world-wide collaboration.
 


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High Redshift Quasars in Next-Generation Spectroscopic Surveys

Quasars are among the brightest lights in our Universe and powered by accretion onto supermassive black holes.  With the advent of very large, highly multiplexed wide-field spectroscopic surveys, we are entering a golden age for studies of quasar demographics where the rest-frame ultraviolet and optical spectra can be used to characterise the accretion and outflow properties in large statistical samples extending out to the highest redshifts when the first galaxies were forming. 
 
The largest sample of spectroscopically confirmed quasars to date comes from the Sloan Digital Sky Survey (SDSS), which has provided us amost a million quasar spectra out to redshifts of 6. On account of the bright flux limit and optical wavelength coverage of SDSS however, it is not sensitive to both more distant and obscured quasars. In the former case the optical light is attenuated by dust around the quasar or in the quasar host galaxy while in the latter case it is redshifted into the infrared region of the electromagnetic spectrum.  
 
As part of this PhD project you will have proprietary access to two new, state-of-the-art spectroscopic survey datasets from the 4MOST spectrograph on the ESO VISTA telescope and the MOONS spectrograph on the Very Large Telescope, which are due to begin observations in 2025. 4MOST can probe an order of magnitude deeper than SDSS and MOONS extends into the near infra-red wavelengths where the effects of dust attenuation are much less marked. As a result, they offer an unprecedented opportunity to extend the census of known quasars into the distant and obscured Universe. How many such quasars are out there? Are their physical properties similar to, or different from the well-established optically selected population from SDSS? The PhD will be observationally driven and motivated by the new findings with the 4MOST and MOONS proprietary data to which you will have access.  
 
You will be part of a vibrant and growing research team at Southampton including PhD students and postdoctoral researchers exploiting the latest multi-wavelength surveys to understand the galaxy formation. The project will give you an opportunity to join the 4MOST and/or VLT-MOONS Guaranteed Time Observation consortia and to work with scientists in the UK, Europe, USA and Chile as well as to develop new skills in spectroscopy of astronomical sources.

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Does It Rain on Other Planets?

Dr. João M. Mendonça invites applications for a 4-year PhD research position in computational modelling of planetary climates. The successful applicant will join the new research group in planetary sciences at the University of Southampton. Thanks to the successful Horizon Europe Guarantee grant, the group will soon grow to 8 members.
 
Project description
 
Titan, the largest moon of Saturn, has a thick atmosphere mostly composed of nitrogen (>97%) and methane (<3%). Methane exists in Titan’s environment in solid, vapour, and liquid forms, and it rains in lakes and seas. The methane cycle on Titan resembles Earth's water cycle, making it an important subject for studying weather patterns in climate models. Despite its similarity to Earth's water cycle, Titan does not have large amounts of methane at its surface, unlike water oceans on Earth. Our current observations of Titan make it an excellent case for validating our current 3D planetary climate models. The ability to accurately simulate weather cycles other than Earth’s water cycle is essential for understanding the climate of other planets, such as exoplanets.
 
The student will use a cutting-edge computational model of planetary climates (OASIS) to create 3D simulations of Titan that go beyond the current state of the art. The student will have access to high-performance computing facilities at Southampton, opportunities to engage in international collaborations, visits to other research groups abroad, and to acquire new skills in modern high-performance computing techniques for simulating the fundamental physics of planetary climates.
 
In this project, the student will develop and implement the weather cycle physics into the group’s existing 3D planetary climate simulations. The goal is for the student to develop 3D simulations of the methane weather cycle in Titan. The student will: a) Create new and unprecedented high-spatial resolution simulations of the methane cycle in Titan. b) Analyze and determine the physical properties of cloud evolution during one Titan year and quantify the physical processes that supply the atmosphere with methane; c) Apply the new model to observations from the James Webb Space Telescope from terrestrial to sub-Neptune planets to unveil the role of weather cycles in exoplanets.
 


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Revealing Quasar Host Galaxies with the Vera C. Rubin Observatory 


The Vera C. Rubin Observatory is a ground-breaking astronomical facility due to start survey operations in 2025. The 10-year Legacy Survey of Space Time (LSST) conducted with Rubin will revolutionise astronomy by mapping the entire Southern sky every few days and generating a petabyte scale dataset containing billions of astronomical sources. Within the rich LSST dataset there will be millions of active galactic nuclei powered by accretion onto supermassive black holes.  
 
In the local Universe supermassive black hole mass is correlated with the stellar bulge mass of the host galaxy but is this also true at high-redshifts? What are the mechanisms by which supermassive black holes and their host galaxies assemble their mass and what role do mergers play in their assembly? It has been challenging to answer these questions because it is difficult to see the starlight within the host galaxies of rapidly growing black holes or quasars due to the glare of the bright quasar, which outshines the host galaxy by several orders of magnitude. LSST's sensitivity to low surface brightness features and image quality makes quasar host galaxies accessible via ground-based imaging. This becomes particularly true in the case of quasars enshrouded by dust as the dust dims the quasar light. Dusty quasars account for a significant fraction of black hole activity in the early Universe and could be a critical phase in the evolution of all massive galaxies.
 
The goals of the PhD will be to systematically characterise the multi-wavelength properties of quasar host galaxies as a function of redshift, luminosity and dust obscuration using imaging surveys. You will benefit from the deep expertise in our research group on astronomical image processing as well as getting the opportunity to work with the first science images from LSST.
 
You will be part of a vibrant and growing research team at Southampton including PhD students and postdoctoral researchers exploiting multi-wavelength data to understand galaxy formation. As part of the wider team, you will explore synergies between LSST and wide-field spectroscopic surveys like 4MOST and VLT-MOONS as well as space-based imaging from Euclid. The project will give you an opportunity to be part of the international LSST Science Collaborations and to work with scientists in the UK, Europe, USA and Chile. You will confront “big data” challenges and develop a range of transferrable skills related to the analysis of large, complex and multi-variate datasets.  



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HUNTING FOR HIDDEN BLACK HOLES AND EXTREME TRANSIENTS USING LARGE SURVEYS 

This is pure blue-skies astronomy research project. The research will be computer-based using publicly available software and well-known mathematical techniques. At this time, internal funding cannot be guaranteed; externally funded candidates are welcome to apply.
 
The research will focus on the theme of hunting for previously unknown black holes in the cosmos. Despite their brightness, these objects can be difficult to find because they are often hidden behind thick veils of interstellar gas and dust, or their presence may be masked in other ways. Understanding their growth has implications for galaxy evolution and cosmology.
 
We now have new telescopes to find these black holes. This is an ideal opportunity for a PhD student to join our group and lead projects exploiting new telescope surveys to answer important questions on the theme of black hole growth. There will be opportunities to learn about astronomical observing and statistical data analysis.
 


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Investigating the fuelling of supermassive black holes using multi-phase gas

Supermassive black holes live in the centre of galaxies and grow by the accretion of gas from their surroundings. This process of black hole growth occurs throughout the evolution of the Universe and powers some of the most spectacular and energetic events we can observe: Active Galactic Nuclei.
 
In this project the student will investigate the physics behind how the gas is transported to the black hole. For this purpose, the student will analyse observations of gas in different phases (atomic, ionised and molecular) and apply physical models to study: 1) the mechanisms by which the gas is transported to the black hole, and 2) how much gas is transported in total, which controls the rate of growth of the black hole. The data will consist of observations from state-of-the-art telescopes, such as ALMA, and the student will have the opportunity to propose and plan for further observations.
 
The student will be part of a local research group at Southampton working on the multiwavelength properties of black holes and galaxies and will also be part of a wider international research team with opportunities for visits and training.
 

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Exploring the impact of misalignment on the appearance of black holes

Black holes grow by accreting material through a disc which is bright across the EM spectrum. There is good theoretical and observational evidence that the accretion disc will likely be misaligned with the spin axis of the black hole although this is presently hard to pin down due to a lack of models which deal with such an effect. Due to misalignment, the resulting general relativistic effect of frame dragging leads to Lense-Thirring torques which drive an increase in the accretion rate onto the hole itself and changes the way it should appear at high photon energies. The details of this process can be explored both analytically and numerically, the latter using simulations of magnetohydrodynamics (MHD) with radiation and GR explicitly included. Using analytical descriptions of accretion, the student will create the first model which describes the emission from a misaligned accretion disc, apply this to data from X-ray satellites and attempt to constrain misalignment directly. The student will also have the opportunity to explore new GR-RMHD simulations which are being carried out by Prof Middleton’s group and explore misaligned accretion at super-Eddington rates.

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Hidden black holes and the search for self-lensing binaries

We know of only 20 or so black holes in our galaxy yet predict there should be 10s of millions! Where are they hiding? It turns out that binary systems containing high mass stars (and so those which go on to produce black holes), evolve through a number of stages; in one such stage there is a black hole or neutron star orbiting at a large distance from a ‘normal’ companion star. This is a very long-lived state which accounts for the vast majority of the millions of binary systems harbouring neutron stars and black holes in our Galaxy. Self-lensing occurs when the binary system is viewed edge-on such that optical light from the companion star is bent towards us and magnified. In the case of microlensing this is a one-off event, whilst self-lensing repeats on the orbital period of the binary allowing it to be distinguished. New citizen science projects are being led by Prof Middleton’s group (black-hole-hunters.org) which permit the vast amount of optical survey data taken by instruments such as TESS to be studied, and self-lensing events searched for. The student will have an opportunity to explore these projects and the results coming from them, the latter involving the modelling and follow-up of any high probability events. The student will also explore the most promising methods for constraining the spin of the compact object being lensed which will involve both theoretical and computational modelling.

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Extreme Physics Around Black Holes: Exploring Accretion Disk Dynamics at the Edge of the Event Horizon

Black holes in our Galaxy, with masses between 5 and 15 times that of our Sun, form when massive stars explode in supernovae. These dense objects are so compact that not even light can escape their immense gravitational pull. Fortunately, some black holes reside in binary systems with companion stars. When the black hole is close enough to its stellar companion, it draws gas from the star, gradually reshaping it into a pear-like form. This pulled gas doesn’t plunge directly into the black hole but spirals inwards, forming an accretion disk—similar to water swirling down a drain.
 
This project aims to answer key questions: What fundamental physics govern the behavior of these accretion disks? What conditions lead to the formation of ultra-fast winds and powerful jets? The PhD student will join the high-energy astrophysics group to investigate these critical aspects of black hole accretion physics. This work will involve analyzing high-time-resolution data from NASA’s cutting-edge X-ray instrument, the Neutron Star Interior Composition Explorer (NICER), alongside data from advanced optical, infrared, and radio observatories.

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Numerical Simulations of Thermonuclear Burning Spread on the Neutron Star Surface

Type I X-ray bursts, or thermonuclear bursts, are explosive events that occur on the surfaces of neutron stars in binary systems. As gas accumulates and spreads across the neutron star's surface, it forms a fresh layer of material. Under the right conditions, this material undergoes gravitational compression and heating, reaching critical temperatures and densities that trigger thermonuclear fusion. This ignition leads to a rapid sequence of nuclear reactions, primarily through the CNO cycle, which quickly converts hydrogen into helium. The result is a powerful release of energy in the form of X-rays—brief bursts that emit more energy in seconds or minutes than the Sun does in an entire week. These bursts provide a valuable observational glimpse into the extreme physical conditions on neutron star surfaces.
 
In this project, the student will simulate the spread of the burning layer on the neutron star’s surface once these critical conditions are achieved. Findings from this research will be compared with observational data and theoretical models. The successful applicant will join the high-energy astrophysics group at Southampton and collaborate with leading researchers from around the world.

Last updated 6 Nov 2024 PhD Admission Coordinator
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