Rhodes heads landmark discovery of space phenomenon

Is it a bird, is it a plane – no, it’s a strangely filamented lobe of plasma in a galaxy far, far away.

Strange new threads link the lobes of plasma in the radio galaxy ESO 137-006 in this image from MeerKAT.

Announcing the discovery on Wednesday, Rhodes University astronomer Dr Mpati Ramatsoku said he and his colleagues were used to the usual picture of a galaxy.

"It consists of a core which hosts a supermassive black hole, shooting out two jets of plasma at speeds close to the speed of light.

"The material within the jets eventually slows down and billows out, forming large radio lobes.

"What makes ESO 137-006 different is that there appear to be multiple, additional filaments linking the lobes."

Ramatsoku is the lead author of a study of the discovery undertaken by an international team of astronomers, including from Rhodes University, using MeerKAT, the state-of-the-art radio telescope in the Northern Cape Karoo.

Launched in 2018, the SA MeerKAT radio telescope is being used to answer fundamental astrophysical questions about the nature of objects in the universe, she explained.

"ESO 137-006 is a fascinating galaxy residing in the Norma cluster of galaxies and one of the brightest in the southern sky.

"It is characterised by two very bright lobes of radio emission that are bent in one direction.

"But now we have this discovery of these new features in the form of multiple collimated synchrotron threads connecting the lobes."

Professor Oleg Smirnov, head of the SA Research Chair Initiative for radio astronomy at Rhodes, said the team was excited.

“Such serendipitous discoveries are very important for MeerKAT because they highlight its incredible capacity for finding the ‘unknown unknowns’ in our universe.”

"Finding something completely unexpected like this is very exciting, romantic even, and it reminds many of us of the reasons we got into science in the first place.”

Ramotsoku said further study to understand the nature of the strange filaments was now required.

“It is possible that they may be unique to ESO 137-006, because of its harsh environment.

"It is equally possible that these features are common in radio galaxies but, so far, we have been unable to detect them due to sensitivity and resolution limits.

"If the latter is true, it raises further questions like how common is this new feature in radio galaxies and why do they exist."

Understanding the nature and physics of the filaments could open a new case for sensitive radio interferometers like MeerKAT and in the future its successor, the Square Kilometre Array (SKA), she said.

Smirnov credited Prof Justin Jonas who had been at Rhodes since his student days and who was awarded the vice chancellor’s distinguished achievement award in 2019.

"He made MeerKAT happen and he brought the SKA to SA."

He said Rhodes was proud of the role it had played in the study.

“Rhodes University may be small, but it only goes to show that you don’t need to be a big university in a big city to do world-leading science." — Herald reporter