About the project
James Webb Space Telescope (JWST) has found black holes that seem too massive, too early. How did they grow so fast? In this project you will build transparent, data-driven models that trace black hole growth from the first seeds, test light, heavy and primordial scenarios against JWST data, and set constraints on how the Universe’s first giants formed.
JWST is finding supermassive black holes within the first billion years of cosmic time, which already weigh millions to billions of suns, comparable to the masses of their host galaxies, and roughly ten times more common than we expected. How did they get so big and numerous so quickly?
This project tackles that question with semi-empirical models: transparent, data-driven numerical tools that connect observations directly to theory. You'll grow black holes along dark matter halo merger trees through gas accretion and mergers, with accretion rates drawn from Eddington-ratio distributions and duty cycles consistent with current data. You'll then start them from different seeds: light (about 100 solar masses, left by the first stars), heavy (10,000 to a million solar masses, from direct collapse) or primordial black holes. Using statistical approaches, you'll ask which seeds and accretion histories can reproduce the JWST active galaxies, including the “Little Red Dots”, and X-ray quasars.
Because every assumption is explicit and can be switched on or off, you'll transparently dissect the main supermassive black hole growth channels and set clear constraints on viable seeding mechanisms by comparing with a variety of data sets both in the local and the high-redshift Universe. If you have a creative and curious mind, this is the project for you.
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.
