The first image of a Black Hole
In April 2019, the Event Horizon Telescope (EHT) announced the first image of a black hole, a historic scientific result and technical achievement that captured the imagination of the public globally.
To achieve this, signals from telescopes across the world had to be combined. This entailed, among other things, an understanding of the specific workings of each telescope and the effect of the Earth’s atmosphere above them. Furthermore, it meant being able to simulate the instruments and the atmosphere, and based on this, to predict what a black hole would look like in the data. Associate Professor Roger Deane, from the University of Pretoria, is a member of the 200-strong team that worked together to produce this breakthrough image and he is building a group to increase South African involvement in this inter-continental project.
Prof. Deane’s role, along with his postdoctoral fellow, Dr Iniyan Natarajan (then at Rhodes University), was to simulate the global telescope array, generating a model of the instrument and atmospheric conditions above each site. The result is a far better understanding of how the imperfect instrument and conditions impact the reconstructed image of the black hole shadow. The simulation can now also be used to predict how adding more telescopes to the array may improve the understanding of the data and images.
The same software can be used to predict the potential of placing radio antennas across the African continent for not just the EHT, but for other instruments like the African Very Long Baseline Interferometry Network and the Square Kilometre Array. Prof. Deane’s team at the University of Pretoria are expanding their EHT involvement, assisted by the IDIA research cloud and bespoke radio astronomy software support onto platforms that enable high-performance computing.
The team is growing. A PhD, a MSc and an Honours student, each of whom will be using the IDIA Cloud are joining the project. Micaela Menegaldo, an IDIA-funded UP MSc student, will be using Prof. Deane’s EHT software in combination with a machine learning algorithm to analyse the effect of weather and instrument parameters on the quality of EHT images. This is especially important given how little telescope time the EHT Collaboration has per year to explore this new window on gravity.?
UP-funded Honours student Heinrich van Deventer will be using the IDIA cloud to perform advanced statistical comparisons of prospective models and how they compare with the EHT data. Another UP-funded PhD position will extend the capabilities of the software, to cater with telescope upgrades and increasing sophistication of the data analysis; to maximise scientific output.
It is an exciting time for black hole and gravity research and a significant amount of IDIA processing power and support is committed to ensuring South Africa is firmly a part of this scientific adventure of discovery.