Cape Town - AFTER two years of research in the effort to piece together the history of the universe, a team of scientists from the University of the Western Cape discovered an astronomical phenomena, known as a megamaser, in a galaxy around five billion light years away.
Scientists say the masers (which eventually became known as a megamaser) are often found when two galaxies collide and merge. The collision of massive clouds of dust and molecules create the conditions for masers to shine very brightly, and given that this particular one was so powerful/bright, it then became known as a megamaser.
Making efforts in finding the first step of studying galaxy evolution from mergers using megamaser detection, Dr Marcin Glowacki, who spent three years at UWC as a Post-Doctoral Research Fellow, stumbled upon the discovery during lockdown.
“One night during lockdown in 2020, and I remember the night well, when we were all stuck indoors in our homes in South Africa, I was looking through the data on my dining room table, and I spotted the megamaser,” said Glowacki.
Once Glowacki started investigating, along with other researchers from various institutions in order to ensure that what they saw was “a real detection”, another night of observation followed.
“We had to verify we saw the same signal in the same position in the sky, and the same frequency and distance away from us. Then there was the process of doing follow-up studies, trying to learn as much as we can about the galaxy and figuring out that this object was a megamaser, and go from there with the peer review process,” he said.
The scientists say the data stemmed from more than 3 000 hours of science project work from the MeerKAT telescope in the Northern Cape. Given the magnitude of the discovery, the astronomical object has been nicknamed “Nkalakatha”, meaning “big boss” in isiZulu.
In an attempt to piece together the history of the universe, the associate director of UWC’s Development and Outreach Department, Dr Carolina Ödman, said the discovery benefited the world of astronomy and physics as it showed that 5 billion years ago, there were galaxies that had formed and evolved enough to contain OH (hydroxyl) massers.
“We have to remember that the object was found amidst observations of neutral hydrogen that emits light in the radio wave part of the electromagnetic spectrum that the MeerKAT radio telescope can see extremely well.
“An OH maser is a molecule made out of one atom of hydrogen and one atom of oxygen. An OH maser emits radio waves at a wavelength very near to that of hydrogen. Dr Marcin Glowacki was analysing hydrogen data when he came across this very bright source. He then checked the wavelength of the light that had been recorded by the MeerKAT and realised that it was in fact a very powerful maser. This was unexpected as no maser’s this powerful have ever been detected that far away yet.
“So, this sets a new boundary for galaxy mergers. It shows that already, 5 billion years ago, such large galaxy mergers did occur, and this therefore has to be the case in our models of the universe too. So it gives us a new piece of knowledge in the fascinating puzzle that is the history of the universe,” said Ödman.
She said the discovery showed that South Africa could also be a leader in the progress of understanding the universe.
“This itself is quite profound as we try to understand where the universe, galaxies, stars, planets, life and, ultimately, we come from. This data also shows the world that South Africa can be a world leader in science and technology, and that changes the image of South Africa to the developed world – it really doesn't hurt to have a good story sometimes. It also shows that no matter how big our challenges, we are capable of dreaming big and of realising projects that grow humanity as a whole,” said Ödman.
The UCT deputy head of the Astronomy Department and associate professor, Sarah Blyth, said that while the discovery was exciting, a big challenge was the quality of physical science and maths at schools.
“We desperately need more qualified teachers who can teach our learners maths and physical science and who can instil the excitement of these sciences in our learners.
“Astronomy is a discipline that teaches students both a wonder for the universe but also excellent problem-solving skills which can be transferred to other careers which benefit South Africa’s economy, such as the technology and data science sectors.
“Some of our postgraduate astronomy students move out of science and into these sectors which help bolster these important parts of the South African economy. Not only that, in South Africa we have the MeerKAT radio telescope and we will soon have the Square Kilometre Array radio telescope and we need more South African scientists and engineers to be able to explore the data from these telescopes to play a leading role in future discoveries,” said Blyth.