The US National Finance Foundation has invested $9.5-million in expanding the Hydrogen Epoch of Reionisation Array (Hera) telescope’s capabilities, which will allow the array to expand to 220 radio dishes by 2018, SKA announced on Wednesday.
Hera, which was recently granted the status of a Square Kilometre Array (SKA) precursor telescope, currently has 19, 14-m-wide radio dishes at SKA South Africa’s Losberg site, near Carnarvon, in the Northern Cape, which will be increased to 37.
Located in the Karoo, the telescope aims to detect the distinctive signature that will enable astronomers to understand the formation and evolution of the first stars and galaxies in the universe.
The Hera radio telescope follows in the footsteps of a precursor instrument called Paper (Precision Array for Probing the Epoch of Reionisation), also located in the Karoo.
However, the much more sensitive Hera, operating with minimal man-made radio interference, will explore the billion-year period after hydrogen gas collapsed into the first galaxies – a few hundred million years after the Big Bang – through the ignition of stars throughout the universe, which created the first structures of the universe we observe today.
SKA South Africa chief scientist Dr Fernando Camilo explained that the funding could increase the chance of detecting the first stars and galaxies ever to be created, from South Africa's Northern Cape.
He explained that the universe was formed in a hot ‘big bang’ of particles and radiation 14-billion years ago, which soon cooled down and was dark for hundreds of millions of years, before any stars formed. Still, nobody yet knows when these stars formed.
SKA South Africa senior astronomer Dr Gianni Bernardi added that Hera – which operates at a low radio frequency – had enough sensitivity to detect cosmic reionisation, noting that SKA hoped to map it “very precisely by statistically measuring how the fraction of neutral hydrogen changed with cosmic time. Hera has the potential to transform our knowledge in one of the main SKA science areas.”
Bernardi added that the telescope's minimalist design made it a relatively inexpensive structure and that, because each antenna would point in a fixed direction, they did not have to move around, therefore, no expensive moving parts were required.
Meanwhile, Hera project engineer Kathryn Rosie noted that Hera was a “truly Karoo-based instrument”, as the construction materials were sourced and fabricated from within South Africa – predominantly from the Carnarvon area.
“Because the bulk materials of construction are light industry materials such as wood and PVC pipes, there is opportunity for local businesses, which don't necessarily have a ‘high technology’ customer base, to be a part of this awesome science instrument,” said Rosie.
She added that local contractors were installing its main support poles, cutting structural elements to size and making up the reflector surface panels from bulk-supplied material. "Similarly, for our construction crew in the prototype phase, we assembled a team of local young people who have taken on the construction and made it their own. Two SKA South Africa interns who were part of the fibre-training programme in 2015, are included in the team of four,” said Rosie.
Among other investigations, SKA South Africa’s MeerKAT telescope will study evolved galaxies in the later universe, while Hera will peer back nearer to the dawn of time, when the first stars and galaxies were being formed. In this way they address complementary scientific questions.