What are mysterious ‘structures’ found in the Milky Way? Astronomers ‘stunned’ by pattern found in space

A survey of the galaxy has revealed hundreds of mysterious cosmic threads pointing towards the supermassive black hole at the heart of the Milky Way. The filaments stretch five to ten light years through space but resemble nothing more than dots and dashes on the vast scale. 

The threads spread from the galactic centre, which is around 25,000 light-years from Earth in something which looks like fragmented spokes on an enormous wheel. Found by an international team, one of the astronomers says they were “stunned” when they saw these. But what are the mysterious structures, how were they found and what do they resemble? Here is what you need to know. 

What are the mysterious ‘structures’ found in the Milky Way? 

Back in the 1980s, astrophysicist Farhad Yusef-Zadeh at Northwestern University discovered gigantic one-dimensional filaments hanging vertically near Sagittarius A* - our galaxy’s central supermassive black hole. Now the team has discovered a new population of shorter threads which are horizontally spread out, like spokes on a wheel from the black hole. 

Yusef-Zadeh suspects the two different populations of filaments have different origins, as the most recent findings look like dots and dashes of Morse code, and are only apparent on one side of Sagittarius A*. The filaments are made up of luminous gas and are thought to be a few million years old. They are thought to have been caused by interactions between the milky way's supermassive black hole and its surroundings. 

Speaking to Northwestern University, Yusef-Zadeh says: “It was a surprise to suddenly find a new population of structures that seem to be pointing in the direction of the black hole. I was actually stunned when I saw these. We had to do a lot of work to establish that we weren’t fooling ourselves. And we found that these filaments are not random but appear to be tied to the outflow of our black hole. 

“By studying them, we could learn more about the black hole’s spin and accretion disk orientation. It is satisfying when one finds order in a middle of a chaotic field of the nucleus of our galaxy.”

They found this new population to be magnetised, where the previous discovery of vertical threads accelerated particles to near light speed, the new population seems to be emitting thermal radiation. Yusef-Zadeh suspects that the threads were created as an outburst of material, around 6 million years ago, created streaks of hot plasma that point towards the black hole. 

How were the threads found? 

The new population was discovered in data collected by the MeerKat radio telescope in South Africa after Yusef-Zadeh and his team were cleaning up data. The shorter, horizontal threads that spread out from the centre of the Milky Way came into focus when the scientists removed the background and filtered noise from the MeerKAT images.

Yusef-Zadeh told The Guardian that “If it wasn’t for MeerKAT these wouldn’t have been detected. We’ve never been able to dedicate that amount of time to the centre of the galaxy.” This research has been published in The Astrophysical Journal Letters.