Hundreds of Mysterious Threads Found in the Heart of the Milky Way

The center of our galaxy, the Milky Way, is home to a plethora of intriguing features – including nearly a thousand mysterious magnetic strands, according to a new telescope image.

The pairs and clusters of wires span nearly 150 light-years in length and are evenly spaced. The bizarre structures are a few million years old and vary in appearance.

Some of them resemble harp strings, waterfalls or even the rings around Saturn. But the true nature of the filaments remains elusive.

Farhad Yusef-Zadeh, a professor of physics and astronomy at Northwestern University, discovered the wires 35 years ago using radio waves. He determined that the wires were made of cosmic ray electrons that were moving their magnetic fields at close to the speed of light.

The origin of these strands, however, remained a mystery. Now, astronomers have been able to find 10 times more wires than Yusef-Zadeh’s previous discovery, using the South African Radio Astronomy Observatory’s MeerKAT telescope.

A study detailing these findings has been accepted for publication in The Astrophysical Journal Letters.

“We’ve studied individual filaments for a long time with a myopic view,” Yusef-Zadeh, lead author of the study and a member of Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics, said in a note.

“Now, we finally see more broadly — a bird’s-eye view filled with an abundance of filaments. Examining just a few strands makes it difficult to draw any real conclusions about what they are and where they came from. This is a watershed in our understanding of these structures.”

The new, detailed image is made up of a mosaic of 20 different observations taken over three years, pointing to the distant center of the Milky Way, located 25,000 light-years from Earth.

In addition to the long strands, the image shows signs of star birth and the remains of stars blown up via radio emissions. Yusef-Zadeh and his research team focused only on the wires and isolated them from the other phenomena captured in the image. “It’s like modern art,” he said.

“These images are so beautiful and rich, and the mystery of it all makes it even more interesting.”

separating the wires

The amount of radiation varied from other energetic cosmic events such as supernova remnants, analysis of the strands showed. Scientists think the strands are more likely related to past activity, caused by the supermassive black hole at the center of the Milky Way, rather than the explosions of stars.

The team also determined that magnetic fields are strongest along the wires.

Studying a larger group of filaments is allowing scientists to better understand them, although many mysteries remain.

“If you were from another planet, for example, and you found a very tall person on Earth, you would assume that all people are tall,” Yusef-Zadeh said.

“But if you do statistics on a population of people, you can find the average height. That’s exactly what we’re doing. We can find the strength of magnetic fields, their lengths, their orientations and the radiation spectrum.”

As the team works to identify each strand, they are still trying to figure out the orderly and equal distance between the clumps of strands, the cause of the particles’ acceleration, or whether they move with time.

“Every time we answer one question, several more come up,” said Yusef-Zadeh. “How do you accelerate electrons close to the speed of light? One idea is that there are some sources at the end of these filaments that are accelerating these particles.”

It is possible that the wires are connected to a discovery by Yusef-Zadeh and his team, made in 2019: giant balloon structures in the heart of the galaxy.

Several studies on the filaments will be published in the future, and scientists hope to find out how they fit into the tangle of objects near the center of the Milky Way.

“We hope to get to the bottom of this, but more observations and theoretical analysis are needed,” he said. “A complete understanding of complex objects takes time”.