Supervisors: Dr. Annagazia Puglisi, Prof. Francesco Shankar
How did the Universe’s most massive galaxies build their bulges? Using new observations from the James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA), you'll test whether galaxy collisions or internal processes shaped galaxies 10 billion years ago, comparing your findings with theoretical models to uncover the origins of the bulges we observe today.
Most stars in the present-day Universe are found in spheroids: giant ellipticals and the bulges of massive discs. These systems formed most of their stars more than 10 billion years ago and have little cold gas left, yet their progenitors were vigorously forming stars in extended, gas-rich discs. How those discs build compact bulges remains a major open challenge in astrophysics.
Recent observations suggest that we may be witnessing the early stages of this transformation in distant galaxies with centrally concentrated reservoirs of cold gas fuelling intense nuclear star formation. However, we still do not know what drives this process. Are galaxy collisions primarily responsible, or can galaxies build their central structures through their own internal evolution? These scenarios predict different observables, notably the spatial distribution of stars and the properties of their cold gas.
In this project, you'll combine observations from the James Webb Space Telescope (JWST) and the Atacama Large Millimeter/submillimeter Array (ALMA) of these progenitors at the peak epoch of galaxy formation, 10 billion years ago, and test which mechanisms best explain the observed structures. Supervised by Dr Puglisi, you will start from in-hand datasets and expand the sample with archival and new observations to measure the spatial distribution of stars (JWST) and cold gas (ALMA). You'll collaborate with Southampton Cosmology researchers to interpret your observations using their state-of-the-art galaxy evolution models. You will obtain robust statistical constraints on which mechanisms drive the assembly of bulges and spheroids.
You'll receive training in the reduction, analysis and interpretation of state-of-the-art astronomical observations, including high-resolution JWST imaging and ALMA interferometric data. You'll develop expertise in multi-wavelength image analysis, structural modelling of galaxies, and spatially resolved measurements of stellar populations. You'll also gain experience in statistical methods to analyse large astronomical datasets, assess uncertainties and test scientific hypotheses. Working closely with researchers in the Southampton Cosmology group, you'll receive training in the use and interpretation of theoretical galaxy evolution models and their comparison with observations. You'll develop transferable skills in scientific programming, data analysis, critical thinking, research communication and collaborative working, with opportunities to present your results at national and international conferences.
Entry requirements
You must have a UK 2:1 honours degree, or its international equivalent, in one of the following:
- physics
- astronomy
- astrophysics
- a closely related discipline
Essential skills:
- strong interest in galaxy formation and evolution and a willingness to learn new scientific concepts and techniques
- familiarity with scientific programming in Python or a similar language, and willingness to further develop these skills
- good analytical and problem-solving skills, with the ability to work independently and collaboratively
- good communication skills and willingness to engage in scientific discussions
Desirable skills:
- previous experience with astronomical data analysis, such as imaging, spectroscopy or other observational datasets
- experience with scientific computing, statistical analysis or modelling, for example through an undergraduate or Master's research project
- familiarity with galaxy evolution, extragalactic astronomy or cosmology
Fees and funding
We offer a range of funding opportunities for both UK and international students. Horizon Europe fee waivers automatically cover the difference between overseas and UK fees for qualifying students.
Competition-based Presidential Bursaries from the University cover the difference between overseas and UK fees for top-ranked applicants.
Competition-based studentships offered by our schools typically cover UK-level tuition fees and a stipend for living costs for top-ranked applicants.
Funding will be awarded on a rolling basis, so apply early for the best opportunity to be considered.
For more information, please visit our postgraduate research funding pages.
How to apply
Apply now
You need to:
- choose programme type (Research), 2027/28, Faculty of Engineering and Physical Sciences
- select Full time or Part time
- search for programme PhD Physics (7089)
- add name of the supervisor in section 2 of the application
Applications should include:
- your CV (resumé)
- 2 academic references
- degree transcripts and certificates to date
- English language qualification (if applicable)
Contact us
Faculty of Engineering and Physical Sciences
If you have a general question, email our Doctoral College (doctoralcollege-admissions@soton.ac.uk).
Project leader
For an initial conversation, email Dr Anna Puglisi (A.Puglisi@soton.ac.uk).
The School of Physics and Astronomy is committed to promoting equality, diversity inclusivity as demonstrated by our Athena SWAN award. We welcome all applicants regardless of their gender, ethnicity, disability, sexual orientation or age, and will give full consideration to applicants seeking flexible working patterns and those who have taken a career break. The University has a generous maternity policy, onsite childcare facilities, and offers a range of benefits to help ensure employees’ well-being and work-life balance. The University of Southampton is committed to sustainability and has been awarded the Platinum EcoAward.
