Predicting the Growth and Mergers of the Most Massive Black Holes from Early Epochs to the Local Universe

Supervisory Team:   Francesco Shankar, Luca Graziani (soton visiting fellow)

Project description

Supermassive black holes, extreme singularities of spacetime, of the order of a million to a billion solar masses, are lurking today in the cores of most galaxies, including our own Milky Way. The masses of supermassive black holes seem to correlate with their host galaxy and dark matter halo properties, in particular to the characteristic random motions (velocity dispersion) of stars. Observations of the deep Universe are showing that supermassive black holes as massive as a billion times the mass of the sun are already present at early epochs, providing extremely stringent constraints to the viable formation channels of these monsters.

This project aims at contributing to the still largely unsolved questions in astrophysics: How do supermassive black holes form and evolve? What are the formation channels for their seeds? How much do black-black hole mergers and gas accretion contribute to their mass growth throughout the history of the Universe?

Via the use of advanced semi-empirical models, which make use of sub-halo abundance matching, coupled to the outputs of high-resolution N-body simulations, this project aims at determining the relative roles of quasar feedback and galaxy mergers in setting the scaling relations with velocity dispersion. In turn, the project aims at constraining the radiative efficiency (and thus the spin) of black holes. The project will also make extensive use of a large hydrodynamic simulation run in Southampton, on IRIDIS5, which for the first time includes the dynamical evolution of stellar mass black holes in protogalaxies as a promising route to form the seeds of supermassive black holes in the early Universe.

This project will also set very stringent constraints on the gravitational wave background from supermassive black hole binaries, of capital importance for the next gravitational wave detectors (LISA). The student will contribute to the next-generation European space galaxy missions, Euclid, LSST, SKA and Athena.

If you wish to discuss any details of the project informally, please contact Prof Francesco Shankar, Astronomy Research Group, Email: F.Shankar@soton.ac.uk, Tel: +44 (0) 2380 59 2150

Entry Requirements

A very good undergraduate degree (at least a UK 2:1 honours degree, or its international equivalent).

Closing date: applications should be received no later than 28 February 2023 for standard admissions, but later applications may be considered depending on the funds remaining in place.

Funding: For UK students, Tuition Fees and a stipend of £17,668 tax-free per annum for up to 3.5 years.

How To Apply

Apply online: Search for a Postgraduate Programme of Study (soton.ac.uk). Select programme type (Research), 2023/24, Faculty of Physical Sciences and Engineering, next page select “PhD Physics (Full time)”. In Section 2 of the application form you should insert the name of the supervisor Francesco Shankar

Applications should include:

Research Proposal

Curriculum Vitae

Two reference letters

Degree Transcripts/Certificates to date

For further information please contact: feps-pgr-apply@soton.ac.uk