PhD Studentship: Uncovering Extremely Luminous Flares from Supermassive Black Holes with Next-generation Survey Telescopes

Supervisory Team: Dr Phil Wiseman

Project description:

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.

Entry Requirements

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

Closing date: 17^th January 2025 but later applications may be considered depending on the funds remaining in place.

Funding: We offer a range of funding opportunities for both UK and international students, including Bursaries and Scholarships.  For more information please visit PhD Scholarships | Doctoral College | University of Southampton  Funding will be awarded on a rolling basis, so apply early for the best opportunity to be considered.

How to apply

Apply online: Search for a Postgraduate Programme of Study (soton.ac.uk) Select programme type (Research), 2025/26, Faculty of Engineering and Physical Sciences, next page select “PhD Physics (Full time)”. In Section 2 of the application form you should insert the name of the supervisor Phil Wiseman.

Applications should include:

• Curriculum Vitae
• Two reference letters
• Degree Transcripts/Certificates to date

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

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