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PhD Projects 2025: Astrophysics

PhD projects in astrophysics for our STFC studentships 2025 are listed below.

Event horizon-scale modelling of radiation from black holes 

Primary Supervisor: Dr Ziri Younsi

In 2019 the Event Horizon Telescope (EHT) Collaboration published the first image of a supermassive black hole (SMBH) from the galaxy M87. In 2022 the EHT then published an image of the SMBH in the heart of our galaxy. These images revealed a bright emission ring enclosing the ‘event horizon’ of the SMBH. Accurate measurements of these images provide new constraints on BH mass and spin, the mechanisms powering accretion and relativistic jet collimation, and even enable novel tests of general relativity. Multi-frequency polarimetric observations from black-hole systems are essential to understand their fundamental properties and governing physical processes. Modelling the electromagnetic (EM) emissions from BHs requires performing magnetohydrodynamics (MHD) simulations of relativistic plasmas in strong gravity for later post-processing using polarised radiative transfer. 

The student will begin by learning to perform MHD simulations of BH accretion, calculating the multi-frequency EM emissions from the vicinity of the event horizon using radiative transfer. The student will then choose to continue with one of the following research directions: (1) flaring events in the Galactic Centre, (2) particle production and acceleration processes around BHs, or (3) strong-field tests of gravity. These directions all provide new observable signatures which will help guide future astronomical observations of strong gravity systems. Throughout the project the student will learn experimental techniques underpinning interferometric imaging of BHs and their research outcomes will contribute to science working groups within the EHT Collaboration.

Desired Knowledge and Skills

  • Required: Undergraduate or MSc in physics or astrophysics
  • Required: firm foundation in general relativity, radiative transfer, and magnetohydrodynamics
  • Required: strong background (and demonstrable prior experience) in analytic and numerical computational approaches
  • Required: creativity and determination
  • Desirable: knowledge in astronomy and interferometric imaging
  • Desirable: running computational codes on shared and distributed memory architectures (OpenMP and MPI)

The host galaxies of QSOs

Primary Supervisor: Prof. Mat Page

The standard paradigm for galaxy formation now has massive black holes in active galactic nuclei playing a key role in shaping the evolution of all substantial galaxies. The objective of this proposal is to examine the inter-relationship of black hole and host galaxy during the epoch when black holes were growing rapidly and shining as quasi-stellar objects (QSOs). Measuring the host galaxies of QSOs has, until now, been a huge problem because the host galaxy emission is totally swamped by the light from the AGN. The superb spatial resolution of ESA’s Euclid satellite, particularly it's VIS instrument, presents an extraordinary capability to disentangle the nuclear and host-galaxy components. Whereas this was possible for small numbers of objects with the Hubble Space Telescope, the many thousands of square degrees that will be covered by Euclid mean that we can do this on an industrial scale, for hundreds of thousands of QSOs. The student will work with the Euclid VIS Lead, Mat Page, to extract and study the properties of QSO host galaxies and address questions like: What do the galaxies look like? What are their rest-frame ultraviolet luminosities? How many stars do they contain, and how much star-formation is taking place? And in what order do black holes and their host galaxies assemble their mass: do massive black holes mature first, or the stellar spheroids that surround them?

Desired Knowledge and Skills

  • Undergraduate in astronomy or astrophysics
  • Strong computational skills

The effect of different environmental physical processes on planet formation

Primary Supervisor: Dr Paola Pinilla

Planets form in disks around young stars, the so-called protoplanetary disks. The physical processes that affect the evolution of protoplanetary disks can affect the main properties of these objects, such as their mass, size, and chemical evolution; which can directly affect the properties of the exo-planets forming in these environments. Typically, protoplanetary disks have been modeled as isolated objects, and most of the external physical processes that can affect their evolution have been neglected. Recent observations of protoplanetary disks demonstrate that disks are often influenced by different external factors, such as: dynamical interactions with other stars (and their disks), external photoevaporation from massive stars in the cluster, and (late) infalling material from the surrounding envelope. In this PhD project, we will perform a deep analysis of observations of protoplanetary disks done from the Atacama Large Millimeter Array (ALMA) to quantify the effect of those external physical processes and compare with state-of-the art disk models that include different internal and external physical processes. The analysis of these data will require machine learning methods to find the best models that can fit the big data from ALMA. The results of this PhD project will quantify the effect that external processes can have in the evolution of disks and the final exoplanet properties. This project will be developed with the co-supervision of Prof. Jason McEwen (MSSL/UCL), and in collaboration with Dr. Kurtovic from the Max-Planck Institute in Germany and Dr. Sierra-Morales (MSSL/UCL).

Desired Knowledge and Skills

  • Undergraduate and master degree in physics, astronomy, or astrophysics
  • Strong computational skills

     Revealing the Milky Way disk formation history with the Gaia data

    Primary Supervisor: Prof. Daisuke Kawata

    European Space Agency’s Gaia mission (launched in Dec. 2013), which MSSL is heavily involved in, has made the third data release in June 2022, which provide the position and velocity measurements for more than one billion of stars in the Milky Way. These big data provide the information of kinematics of stars in the large fraction of the Milky Way disk for the first time. We are currently applying a Bayesian neural network model to measure the age and metallicity for the stars observed with the Gaia and ground-based spectroscopic survey. The combined information of the age, metallicity and kinematics for stars in the different region of the Milky Way disk must tell us the formation history of the Milky Way disk. However, secular evolution mechanisms, such as radial migration due to the bar and spiral arms of the Milky Way, and kinematic heating by the bar, molecular clouds and satellite interactions, move the stars from their birth place, making the current stellar structure different from the initial structure when they were born. Hence, to decipher the Milky Way disk formation history from the observational data of the current Milky Way, this project will develop a data-driven machine-learning-assisted Bayesian model of the Galactic disk formation, including the inside-out disk growth, radial migration of stars and heating mechanism. Then, we will fit the Gaia data with the model, to reveal the formation history of the Milky Way disk and the significance of the radial migration and heating.

    Desired Knowledge and Skills

    • Undergraduate in astrophysics
    • Basic knowledge of galactic astronomy and research experience in galactic astronomy
    • Strong computational skills

    Understanding small exoplanets using TESS and PLATO

    Primary Supervisor: Dr Vincen Van Eylen

    The possibility of planets orbiting other stars has been a topic of fascination for centuries. We are the first generation that has brought these planets – now known as exoplanets – from the realm of science-fiction into that of science. An important milestone was the discovery of several planets orbiting a pulsar (Wolszczan & Frail, 1992), followed by the first planet orbiting a star more similar to our Sun (Mayor & Queloz, 1995), an achievement awarded the 2019 Nobel Prize in Physics. The 30 years since have been filled with an abundance of exciting discoveries and today we know over 5000 exoplanets. These planets exhibit an incredible diversity of properties. Why do so many planets have tiny orbits – often much smaller than that of Mercury? What causes planets to become rocky, gaseous, or something in between? Why do some planets have orbits that are strongly eccentric, or misaligned with the rotation of their host stars? What happens to planets when stars evolve away from the main sequence? Which planets are the most favourable and interesting targets for studies of their atmospheres? How unique is our solar system – are we alone?

    Exoplanet science is a young field of research and there is great potential for many ground-breaking new discoveries. A PhD project is available that seeks to understand the properties of small exoplanets, known as (super-)Earths and (sub-)Neptunes. These two categories of planets are distinct in their formation history and atmospheric properties, and may have different core compositions. This PhD project aims to better understand the population statistics of these planets and the link to the properties of the stars they orbit. The project will be powered by observations from the ongoing NASA TESS mission, as well as from the upcoming ESA PLATO mission which will be launched in December 2026. We will use state-of-the-art statistical techniques, including Bayesian statistics and machine learning. The successful applicant will have the opportunity to shape the direction of the project.

    During this project a motivated student will sharpen their analytical background and physical knowledge, while developing strong data science skills that will be valuable both in an academic career and outside of academia. Furthermore, there will be ample opportunity to travel to other universities and present new findings in international conferences, as well as the potential to conduct novel observations at telescopes around the world. The successful applicant will join a vibrant and diverse research team (see www.vincentvaneylen.com for details on ongoing research projects), with ample opportunity to develop both technical and soft skills.

    Desired Knowledge and Skills

    • Undergraduate in astrophysics, planetary science, computer science, or related degree.

    • A background in physics and/or data science is helpful but lack thereof can be overcome with strong motivation. Alternatively, a motivated student with a strong background in computer science or data science rather than astrophysics will also be considered.

    • Excellent writing and presentation skills are a bonus, as is evidence of motivation, leadership and creativity.

    Supermassive black holes in the early Universe

    Primary Supervisor: Prof. Kinwah Wu

    Supermassive black holes are the most fascinating objects in the Universe. There are still many unanswered questions about them. How were they formed in the very early Universe? What is their mass spectrum? How does black-hole spectrum evolve over time? With the launch of JWST and the advancement in large ground-based observational facilities, in particular the ESO VLT and ELT, we can now study these massive compact objects at red-shifts as high as z = 10, where the Universe was younger than 700 million years old. At this time galaxies hosting these black holes were in an infant stage. With the coming of the space-based gravitational wave observatory LISA we will also be able to study these objects in another dimension. Black holes are expected to grow their masses through accretion of gas and mergers. The latter will produce gravitational waves that are in the wavebands of LISA. In addition to electromagnetic waves and gravitational waves, it is believed that black-hole systems are also factories of ultra-high energy cosmic rays.

    The objective of the project to understand the physical processes associated with supermassive black holes in the distant Universe. There are three options for the theme in the PhD study, and the candidate may consider one of the following in the PhD study:

    1. the multi-messenger signatures of binary supermassive black holes in the early Universe during the merger phase;
    2. the production of ultra-high energy cosmic rays in black-hole systems and the associated hadronic and leptonic processes that give rise to neutrino emission;  
    3. the electromagnetic waves and gravitational waves from mergers of black holes with uneven masses.

    The students are encouraged to discuss with the supervisor to settle for a research theme and the final details of the research project.

    These are pioneer study in the forefront of astrophysical black-hole research. The goal is to produce high-quality ground-breaking science in the domains of multi-messenger astrophysics of gravitational wave sources and of ultra-high energy particle astrophysics of black-hole systems.

    The student is required to have a solid training in physics or astrophysics and is comfortable with scientific coding and numerical calculations. Knowledge in high-energy astrophysics and differential equation is desirable. Previous experience in astro-particle physical or gravitational-wave and relativistic astrophysical research is desirable but not essential. 

    Desired Knowledge and Skills

    • undergraduate or MSc in physics or astrophysics. (Required)
    • a solid grounding in electromagnetism, classical mechanics and quantum physics. (Required)
    • comfortable with analytical calculation and computation. (Required)
    • open-minded and resourceful. (Required)
    • knowledge in astronomy is desirable. (Desirable)
    • numerical computation experience. (Desirable)