SA continues to boldly go where no man has gone before

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When it bid to host the Square Kilometre Array (SKA), South Africa embarked on a journey that would place the country as one of the world’s most important radio astronomy hubs. While the project is in its infancy, this vision is already becoming a reality, with a number of discoveries providing astronomers with new insights into the universe.

Hirax
     Assembly of the first 6-m prototype dish on the roof of the Durban University of Technology.

Now a new telescope is being unveiled that will be built at the SKA South Africa site in the Karoo. The Hydrogen Intensity and Real Time Analysis eXperiment (Hirax) is a multimillion-rand radio telescope that will probe dark energy properties and mysterious radio flashes during the universe's critical period, which was between seven billion and 11 billion years ago.

Dark energy is a mysterious force driving the accelerated expansion of our universe. Hirax can study it using a unique cosmic ruler provided by nature, called baryon acoustic oscillations. These were generated in the very early universe, which was a hot and dense soup of particles and light. Small irregularities gave rise to sound waves in this primordial soup.

Fast radio bursts are mysterious millisecond flashes that are hard to detect and localise because they’re so brief and most telescopes only observe a small region of the sky. Hirax’s large field of view will allow it to observe large portions of sky daily, so when the flashes happen, the instrument will be more likely to see them.

Scientists don’t know what causes them, but Hirax will be able to figure out exactly where in the sky these fast radio bursts occur, hopefully leading to a better understanding of the phenomenon. By working with several other Southern African countries to build eight-dish outrigger arrays, Hirax will help localise these bursts to within their hosting galaxies.

Jointly funded by the University of KwaZulu-Natal (UKZN) and the Department of Science and Technology (DST) through the National Research Foundation, Hirax is made up of 1 024 six-metre identical closely packed dishes that will map about a third of the sky during its four years of observation. Hirax is an interferometer array, meaning that it will combine signals from many telescopes to provide the resolution of a larger telescope – allowing it to see more of the sky.

Speaking at the launch of the telescope, Science and Technology Minister Mmamoloko Kubayi-Ngubane said that the project will help South Africa develop innovative solutions, particularly in instrumentation and big data processing, directly impacting other economic sectors through technology transfer. In addition, it will contribute to “human capital development” by training the next generation of scientists for the SKA.

Students working on the project will be trained in all aspects of the telescope, from engineering to science. According to Kubayi-Ngubane, training PhD students during the project will contribute to achieving government’s target of 100 PhDs per million of the population by 2030.

Some scientists have posited that dark matter and dark energy may not exist. Hirax will provide the data that will prove or disprove the current theories. Whether we gain a better understanding of dark matter or merely discover that it doesn’t exist in the way we thought it does, Hirax will provide a vital tool in our understanding of the universe, broadening South Africa’s scientific capabilities and reputation at the same time.

Image credithttps://www.acru.ukzn.ac.za/~hirax/