University of Pretoria-led team harnesses the power of MeerKAT and powerful gravitational lenses to break new ground
Astronomers using the MeerKAT radio telescope in South Africa have discovered the most distant hydroxyl megamaser ever discovered. It is located in a violently merging galaxy more than 8 billion light-years away, opening up new frontiers in radio astronomy.
Hydroxyl megamasers are natural “cosmic lasers”, extremely bright radio-wavelength radiation produced when hydroxyl molecules in gas-rich merging galaxies collide with each other. These cosmic collisions compress the gas and stimulate a large reservoir of hydroxyl molecules that amplify radio emissions. The physical mechanism is very similar to lasers on Earth, but rather than the optical light that our eyes can see, they operate with light at a much longer wavelength of about 18 centimeters. If this special radio light is very bright, it is called “radio light”. mega macer – A “cosmic beacon” that can be seen across vast expanses of space.
This newly discovered star system, HATLAS J142935.3–002836, is so far away that we are seeing what the universe looked like when it was less than half its current age. It is also the most distant and brightest known. In fact, it’s bright enough to deserve the classification Gigamaser rather than Megamaser. Despite the distance, it produced a surprisingly strong signal. This is due to the combination of MeerKAT and a phenomenon known as strong gravitational lensing, which was theorized by Einstein.
“This system is truly extraordinary,” said Dr. Thato Manamela, a SARAO-funded postdoctoral researcher at the University of Pretoria and lead author of the new study. “We’re seeing the radio equivalent of a laser on the far side of the universe. Not only that, but on the way to Earth, the radio waves are further amplified by perfectly aligned but unrelated foreground galaxies, which, because their mass curves local spacetime, Much like a drop of water on a lath, it acts as a lens. So there’s a radio laser that passes through the space telescope before being detected by the powerful MeerKAT radio telescope, all of which together make a wonderful “serendipitous discovery.” ”
Illustration of a distant galaxy (red) 8 billion light years away. It is enlarged by an unrelated foreground disk galaxy, giving rise to a red ring. Splitting the radio light into different colors like a prism reveals the Hydroxyl Gigamaser (the rainbow-colored line in the upper right). Image credit: Interuniversity Institute for Data Aggregation and Astronomy (IDIA)
MeerKAT’s design is well suited for detecting weak radio emissions at centimeter wavelengths. However, collecting data is only part of the challenge. Before breakthrough discoveries are possible, astronomers must carefully orchestrate and analyze terabytes of information using advanced algorithms and scalable computing platforms.
“This result is a strong demonstration of what MeerKAT is capable of when combined with advanced computational infrastructure, a fit-for-purpose data processing pipeline, and highly trained software support personnel,” said study co-author Professor Roger Dean, Director of the Interuniversity Institute for Data Integration and Astronomy (IDIA) and Professor at the University of Cape Town and the University of Pretoria. “This synergistic combination will enable young South African scientists like Dr. Manamela to lead cutting-edge science and compete with the world’s best scientists.”
Hydroxyl megamaser is a rare phenomenon. Previous studies have tracked the most active galactic collisions and have shown that huge reservoirs of gas are fueling intense starbursts and feeding the central black holes. Systematic investigations, such as those conducted by MeerKAT’s detailed survey, promise to turn these once-rare discoveries into powerful explorations of the evolution of the universe.
“This is just the beginning,” Dr. Manamela said. “We don’t want to find just one system, we want to find hundreds or even thousands of systems. Here at the University of Pretoria, we are conducting a systematic survey of the universe and building the necessary computational pipelines and algorithms to pioneer this observational frontier forward and eventually with square kilometer arrays.”
This discovery is driven by the strong partnership between IDIA and SARAO to deliver MeerKAT science and prepare for the SKA era, highlighting South Africa’s growing leadership in data-intensive radio astronomy.
Paper accepted and published Monthly notices and preprints of Royal Astronomical Society Letters can be accessed through the following link: https://arxiv.org/abs/2602.13396.
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