Roger Deane is a Professor in Astrophysics at the University of the Witwatersrand (WITS), and an Extraordinary Professor at the University of Pretoria (UP). He completed his doctorate in 2012 at the University of Oxford and carried out postdoctoral research at Rhodes University and the University of Cape Town.

In 2018 he moved to UP, where he established the Radio Astronomy Research Group. In late 2020, he took up the DSI/NRF SKA Chair in Radio Astronomy at WITS, where he currently serves as Director of the WITS Centre for Astrophysics. His 18 July 2022 NITheCS Colloquium is titled ‘The black hole at the centre of our Milky Way and Africa’s potential future contributions to the Event Horizon Telescope’.

Scientific interests

‘My scientific interests are fairly broad, but are primarily centred on trying to understand how galaxies and their black holes evolve over cosmic time using radio telescopes. I also have strong technical interests, including applying sophisticated algorithms in creative ways to explore some of the powerful new datasets being collected by new instruments,’ says Roger.

Today, he uses the power of next-generation radio telescopes such as South Africa’s MeerKAT. This is a precursor to the Square Kilometre Array (SKA), and Very Long Baseline Interferometers like the Event Horizon Telescope (EHT).

During the NITheCS Colloquium, Roger will discuss the first EHT observations of Sagittarius A* (Sgr A*), the Galactic centre source associated with a supermassive black hole. He will also talk about ‘the bright future of the black hole imaging enterprise. Southern Africa has strong geographic and technical advantages in hosting future EHT stations to enable higher precision tests of gravity, particularly of Sgr A*, which passes directly above us in the southern sky. Expanding the EHT to African soil would spur newfound collaboration between the local high-energy, computational, theoretical and experimentalist (astro)physics communities.’

The joys and challenges of astronomy

Roger grew up in the small town of Welkom in the Free State. ‘While I was always enthralled by the night sky, I never dreamed I could grow up to do this. Scientific research can be immensely challenging on an intellectual and emotional level, but every day I feel grateful, humbled and privileged to be an astronomer. That is thanks to some lucky breaks, hard work and some wonderful people who have supported me over the years,’ he continues.

‘What I love about astronomy are the contrasts and diversity. Observing the cosmos can make humanity seem insignificant and special at the same time. It’s one of the oldest scientific disciplines but is at the forefront of the big data and machine learning revolution. It’s the study of the very large, often using the physics of the very small. While it’s a comparatively small community to other scientific disciplines, we are have a rich, wide-spread and diverse international community. Thought-provoking contrasts such as these seem to be a recurring theme in astronomy.’

A remarkable period ahead

Roger says the next decade will be ‘ambitious and exciting for astrophysics and cosmology, with cutting-edge telescopes like the SKA on the horizon. I expect we will see spectacular new breakthroughs that expand astronomy’s proud history of pushing the frontiers of fundamental physics and innovative technology. Current students and early career researchers will be at the forefront of this remarkable period ahead.’

Here is a short video with Prof Deane: