Astronomers have discovered a giant radio galaxy with plasma jets stretching an incredible 3.3 million light-years—32 times the size of the Milky Way.
This massive structure was found using South Africa’s MeerKAT telescope and has been nicknamed Inkathazo, which means “trouble” in isiZulu and isiXhosa.
The name reflects the challenge scientists face in understanding its unusual behavior.
Giant radio galaxies (GRGs) are enormous structures powered by supermassive black holes at their centers.
These black holes release jets of hot plasma that travel millions of light-years through space.
The jets glow brightly at radio frequencies, which is how telescopes like MeerKAT can detect them.
GRGs were once thought to be rare, but new telescopes have shown there are likely many more waiting to be discovered.
“The number of GRG discoveries has exploded in the past five years,” said Kathleen Charlton, a Master’s student at the University of Cape Town and the lead author of the study.
Inkathazo is different from other GRGs. Its plasma jets are not straight—they bend in unusual ways.
Even more puzzling, the galaxy is located in the center of a galaxy cluster, where the environment is crowded with hot gas and other galaxies. Normally, this kind of environment would make it harder for the jets to grow so large, yet Inkathazo has managed to stretch out to a record-breaking size.
This discovery raises questions about how GRGs form and evolve. “Finding a GRG in a cluster environment challenges what we thought we knew about these giant galaxies,” said Dr. Kshitij Thorat from the University of Pretoria, a co-author of the study.
Using MeerKAT’s advanced capabilities, researchers created detailed “spectral age maps” of the galaxy. These maps track the age of the plasma in different parts of the jets, helping scientists understand how they grow and change. The results showed some unexpected features, such as areas where electrons gained extra energy, possibly from collisions with hot gas in the galaxy cluster.
Inkathazo is the third giant radio galaxy found in a small patch of sky called “COSMOS.” This patch is about the size of five full moons. All three GRGs were spotted with MeerKAT, showing that the southern sky is full of undiscovered treasures. “MeerKAT is perfectly located to uncover more of these giant galaxies,” said Dr. Jacinta Delhaize, who led an earlier study of the region.
MeerKAT is a precursor to the Square Kilometer Array (SKA), a powerful telescope expected to start operating later this decade. The SKA will push the boundaries of radio astronomy even further, helping scientists solve some of the mysteries surrounding objects like Inkathazo.
“We’re entering an exciting era of discovery,” said Dr. Delhaize. “With MeerKAT and soon the SKA, we hope to learn more about these giant galaxies and their role in the universe.”
Source: Royal Astronomical Society.
