Imaging black hole shadows with earth-sized telescopes was discussed by the University of Pretoria’s Professor Roger Deane at a public presentation hosted by the Astrophysics and Cosmology Research Unit (ACRU) in UKZN’s School of Mathematics, Statistics and Computer Science (MSCS).
The topic stemmed from the Event Horizon Telescope (EHT) collaboration which revealed the first ever image of a black hole. This achievement required a large international effort, involving more than 200 scientists from five continents who used a technique that synthesised a virtual telescope with the effective diameter of the Earth.
Apart from providing visual confirmation of the existence of black holes, the size and shape of the shadow feature can provide a stringent test of Einstein’s General Theory of Relativity in the strong-field regime.
Deane, who is in the Department of Physics at the University of Pretoria, was among the 200 scientists who worked on the EHT Collaboration.
His research focuses on the MeerKAT and Square Kilometre Array (SKA) projects with specific interest in the study of supermassive black holes, strong gravitational lensing, and the evolution of distant galaxies. In addition, he has a keen interest in radio astronomy techniques.
In his talk, Deane provided an overview of instruments used and the key scientific results, discussing the future prospects of this exciting field.
EHT is an interferometer and ACRU has several people working on interferometric data from other instruments, such as MeerKAT, Giant Metrewave Radio Telescope (GMRT), Hydrogen Intensity, and Real-time Analysis eXperiment (HIRAX) which is a UKZN flagship project lead by the ACRU.
The EHT result is of importance to all astronomers and scientists as it heralds the beginning of a new era, where astronomers are pushing the boundaries of what technology and science have been able to achieve thus far.
Said Astronomy post-doctoral student at UKZN Dr Kenda Knowles: ‘I really enjoyed Dr Deane’s talk – he broke down complex concepts into understandable pieces and made it very clear how they all fit together. It’s exciting that South Africa is involved in such a project and I hope school learners who attended felt inspired to pursue science and astronomy.’
UKZN Chemistry student Ms Aarti Simren said: ‘I found the presentation fascinating. Professor Deane explained every aspect of imagery in a concise, accessible way. I strongly believe that academia is pointless unless it’s accessible to the average person and Professor Deane was successful in his analogies and explanation of the data, and the series of events leading up to the image. I learned a lot about the process generating the image, thus growing my interest in the subject.’
Grade 12 pupil Ms Marie Mélanie Mercure said: ‘The talk was enlightening and gave me good reason to further my studies in the field. There are so many questions about the universe which are mostly only vaguely answered using mathematic equations or theories. So the fact that we were finally able to prove something that has been questioned for so long is like “wow”. Professor Dean managed to explain something so complex in such a simple way.’
UKZN’s Professor Ritu Goswani said: ‘Professor Deane is the only South African in the EHT collaboration and we are grateful he could afford us his time. It shows that South Africa can produce high quality scientists who are making an impact on the global science stage.’
Words: Leena Rajpal
Background image: T Bronzwaer, J Davelaar, M Moscibrodzka, H Falcke/BlackHoleCam