Azra Hoosen | ah@radioislam.co.za
8 February 2025 | 10:00 CAT
2 min read

South Africa’s MeerKAT telescope has once again made waves in the astronomical community with the discovery of a massive radio galaxy named ‘Inkathazo’, which means “trouble” in isiXhosa and isiZulu. The discovery, led by Dr Jacinta Delhaize, a lecturer at the University of Cape Town, has left scientists both excited and puzzled due to its unusual characteristics and extreme size.

A giant radio galaxy is a type of galaxy with a supermassive black hole at its center, which emits massive jets of plasma into space. In an Interview on Radio Islam, Dr Delhaize explained that there is stuff like gas and dust falling into the black holes. “The black hole is basically feeding and gorging itself and growing bigger. And as it’s doing this, for some reason that we don’t really understand, it’s sending these jets of plasma, which is really, really hot, fast-moving gas, streaming out into space,” she said.

These jets can grow larger over time, leading to the formation of what scientists call giant radio galaxies. The excitement surrounding MeerKAT’s discovery stems from the fact that these galaxies were once thought to be rare. “Then we switched on the new generation of radio telescopes like MeerKAT, South Africa’s MeerKAT telescope, and then they just kind of popped up everywhere on the sky,” said Dr Delhaize.

The name, chosen by Dr Delhaize’s master’s student Kathleen Charlton, perfectly captures the challenge this galaxy presents to researchers. “Basically, it gave her a lot of trouble when she was trying to understand the plasma physics of what was going on here,” she shared.

What makes Inkathazo particularly intriguing is its unexpected location. Scientists previously believed that these giant radio galaxies could only exist in low-density environments, where there were few neighbouring galaxies to interfere with their jets. “But this one, Inkathazo, it’s at the center of a cluster of galaxies. So actually in one of the most dense parts of the universe, which is very confusing for us,” she explained.

Additionally, the plasma jets of Inkathazo are not ageing as expected. “We managed to basically measure the age of the plasma at different points along it, and it’s not behaving according to how we think they should behave. And so, yeah, basically, that’s why it’s troublesome,” Dr. Delhaize said.

One of the plasma jets of Inkathazo has also taken on a strangely curved shape, further complicating scientists’ understanding of these galaxies. Dr. Delhaize compared it to how wind affects hair while running: “As Inkathazo is traveling through the intracluster medium, through this hot gas around it, the jets are kind of like your hair getting blown backwards, and that’s why we think that they’re bending.”

MeerKAT’s Unexpected Findings

MeerKAT’s advanced capabilities have allowed astronomers to detect multiple giant radio galaxies in just a small section of the sky, leading them to rethink their rarity. “We just looked at one sort of semi-random patch of sky, and then all of a sudden, there were three giant radio galaxies in this one tiny patch of sky. And that’s quite remarkable,” said Dr. Delhaize.

Previously, only about 800 of these galaxies had been discovered in the past 50 years, but the MeerKAT findings suggest that they might be far more common than previously believed. “Either we were extraordinarily lucky in the patch of sky that we chose, or they’re much more common than we previously thought,” she noted.

To better understand the mysteries surrounding Inkathazo, astronomers are now preparing for the next generation of observations with the Square Kilometre Array (SKA) telescope. “MeerKAT is great because it has very good resolution. But we’re moving towards the SKA in the future, the Square Kilometre Array Telescope, which will be one of the biggest science projects in the entire world ever undertaken,” she explained.

This global project, partly hosted in South Africa’s Karoo, will allow scientists to capture even more detailed images of galaxies and possibly uncover new physics behind radio jets.

Advice for Aspiring Astronomers

For those curious about space and looking to explore astronomy, Dr. Delhaize has one key piece of advice: “Stay curious, look up.” She encourages people to take advantage of the wealth of space discoveries happening globally, from the James Webb Space Telescope to South Africa’s very own MeerKAT and SALT telescopes.

She also recommends The Cosmic Savannah, a podcast where professional astronomers explain the latest astronomical discoveries in an accessible way. “You can find it online or on Spotify or wherever you get your podcasts,” she said.

MeerKAT’s discoveries continue to position South Africa at the forefront of global astronomy research. “It’s not just about gazing at the stars and their beauty, but all of the other things that are happening that we really can’t see without those wonderful telescopes. I think as South Africans, we’re very proud to know that it’s our telescopes here that are bringing all of this information to the world,” said Dr. Delhaize.

LISTEN to the full interview with Muallimah Annisa Essack and Dr. Jacinta Delhaize, a lecturer at the University of Cape Town, here.