The SKA Observatory (SKAO) has reached a significant milestone in South Africa: two of its SKA-MID radio telescope dishes have successfully operated as an interferometer for the first time, marking a key step toward full scientific operations.
The SKAO telescopes are currently under construction across two sites in Southern Africa and Western Australia. It is the largest radio astronomy facility ever built, and is designed to study the universe by collecting faint radio signals with unprecedented sensitivity and resolution.
Interferometers like SKA-MID and SKA-LOW combine signals from multiple dishes, antennas or telescopes to function as a single, much larger instrument. The term “fringes" refers to the successful combination of signals from two or more antennas or dishes that interfere with each other to cause a fringing pattern, a critical test of system performance.
For this new achievement, two 15-metre SKA-Mid dishes observed a distant radio galaxy approximately 2.6 billion light-years away, demonstrating the ability of the dishes to work in concert.
First true test
Professor Philip Diamond, SKAO Director-General, said “This is the first true test that all our systems are working together, and that the SKA-Mid telescope is alive as a scientific instrument."
“Having each dish observe the sky individually is an achievement, but having them operate in concert as one telescope is a much bigger technical challenge, and our teams have now achieved that milestone."
This result confirms that the SKAO hardware and software systems are working as expected.
Building Towards 197 Dishes
SKA-Mid now has seven dish structures assembled on site in the Northern Cape, with a further 12 on their way from the manufacturers CETC54 in China. When complete the telescope will comprise 197 dishes, including the integration of the existing MeerKAT radio telescope built and operated by the South African Radio Astronomy Observatory (SARAO).
UK Role
Alongside hosting the Global Headquarters at Jodrell Bank in Cheshire, UK teams are playing a pivotal role in delivering key technologies for the SKA-Mid telescope in South Africa.
Much of the UK research and development is being funded by the Science and Technology Facilities Council (STFC).
UK contributions include:
- Observatory Science Operations software led from the UK Astronomy Technology Centre, along with UK and Indian industrial contributions
- Data handling and processing solutions from STFC's Rutherford Appleton Laboratory and the University of Cambridge to manage the telescope's vast data output
- Pulsar search systems from the Universities of Oxford and Manchester, enabling studies of neutron stars and gravitational waves
In addition, UK companies have won contracts to contribute to SKAO construction, including:
- Cryocoolers and ruggedised compressors from Oxford Cryosystems Ltd
- Synchronisation and timing (SAT) Timescale from GMV UK Ltd
- Telescope control systems from Observatory Sciences Ltd
Dr Laura Wolz, UK representative to the SKA Science and Engineering Advisory Committee and Reader at the University of Manchester, said: “The first fringes at SKA-Mid is such an important milestone towards the operation of all SKA telescopes. Now the astronomy community is getting excited for first scientific data from the telescopes. This really represents the culmination of decades of design and construction work and is a great achievement for the global collaboration supporting the project."
Prof Pamela Klaassen, SKA PI for the UK Astronomy Technology Centre, said: "First with SKA-LOW, and now with SKA-MID, the decades of hard work put in by scientists, engineers and technicians are starting to come together into the envisioned next-generation global observatory. I can't wait to see what comes next!"
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