North-West University 4-dish Interferometer

by Prof. James Chibueze

Some parts of the invisible components of the universe, like massive jets of radio galaxies, halos and relics of Galaxy Clusters, magnetic fields of astronomical objects, can be studied at radio wavelengths. In recent times, the field of radio astronomy has significantly expanded with the advent of new and upgrades instruments like the Atacama Large Millimetre/submillimetre Array (ALMA), the Very Large Array (VLA), MeerKAT and the upcoming Square Kilometre Array (SKA).

MeerKAT and the part of the SKA that will be hosted in South Africa underscores the need for growing human capacity in radio astronomy and interferometry in the country and the continent at large. The Centre for Space Research, North-West University has actively trained and produced impactful MScs and PhDs for many years and has taken up the responsibility of developing a teaching interferometer that can also be used for doing research studies of bright radio sources. The interferometer consists of 4 x 3.7m radio telescopes. These are installed at the Nooitgedacht farm of the North-West University, 35 km outskirt of Potchefstroom. The site is fairly radio quiet and very sparsely populated.

The telescopes were installed in August 2022 and are undergoing commissioning and will be in full operation by 2024. Each telescope can operate at L-band and C-band, however, feeds will need to be swapped out to change from one band to another. The backend is a wideband receiver covering from 1 GHz to 18 GHz, thus allowing for future expansion of the science cases.

To underscore that this is a training instrument, I note that the telescopes were assembled by students and a student is leading the commissioning and verification of the telescopes. We have also attracted a huge number of collaborations. For example, Prof Tinus and Dr Johan of University of Pretoria are keen to develop new receivers and test/install them on our telescope and they have visited our site, the University of California, Berkeley SETI Team are collaborating with us on possible SETI high-cadence observations of SETI targets.

It is our hope that the NWU 4-dish interferometer will help bridge the knowledge gap in the country and continent in preparation for the SKA and also for the use of the current MeerKAT.