In the center of the Milky Way there are nearly 1000 mysterious filaments

Using observations at radio wavelengths, Farhad Yusef-Zadeh of Northwestern University discovered highly organized magnetic filaments as early as the early 1980s. light speed. But their origin has remained an unsolved mystery.

Now, the new image has shown 10 times more filaments than previously discovered, allowing Yusef-Zadeh and his team to conduct statistical studies on a large population of filaments. This information could potentially help them finally unravel the mystery.

"We have been studying individual filaments for a long time with a myopic view," said Yusef-Zadeh, lead author of the article. "Now, we finally see the big picture: a panoramic view full of an abundance of filaments. Examining certain strands alone makes it difficult to draw real conclusions about what they are and where they come from. This is a watershed to further our understanding of these structures. ”

Yusef-Zadeh is professor of physics and astronomy at Weinberg College of Arts and Sciences at Northwestern and a member of the Center for Interdisciplinary Exploration and Research in Astrophysics ( THERE WAS). To build the image with unprecedented clarity and detail, astronomers spent three years surveying the sky and analyzing data at the South African Radio Astronomy Observatory (SARAO). Using 200 hours of time on SARAO's MeerKAT telescope, the researchers put together a mosaic of 20 separate observations of different sections of the sky towards the center of the Milky Way galaxy, 25,000 light-years from Earth.

To visualize the filaments on a finer scale, Yusef-Zadeh's team used a technique to remove the background from the main image in order to isolate the filaments from surrounding structures. The resulting image astounded him. While many mysteries surrounding the filaments remain, Yusef-Zadeh was able to piece together multiple pieces of the puzzle. In their latest article, he and his collaborators specifically explored the magnetic fields of filaments and the role of cosmic rays in illuminating magnetic fields.



The variation in radiation emitted by filaments is very different from that emitted following a supernova explosion, suggesting that the phenomena have different origins. It is more likely, according to what the researchers found, that the filaments are linked to the past activity of the Milky Way's central supermassive black hole, rather than to supernova explosions. The filaments could also be related to huge radio-emitting bubbles, which Yusef-Zadeh and collaborators discovered in 2019.

And, while Yusef-Zadeh already knew that the filaments are magnetized, he can now say that magnetic fields are amplified along the filaments, a primary characteristic that all filaments share. "This is the first time we have been able to study the statistical characteristics of the filaments," he said. "By studying the statistics, we can learn more about the properties of these unusual sources.

" If you came from another planet, for example, and you met a very tall person on Earth, you could assume that all people are tall . But if you do statistics on a population of people, you can find the average height. This is exactly what we are doing. We can find the strength of the magnetic fields, their lengths, their orientations and the spectrum of radiation ”. Among the remaining mysteries, Yusef-Zadeh is particularly perplexed about how the strands appear structured between them. The filaments inside the clusters are separated from each other at perfectly equal distances, about the distance from the Earth to the sun.

"They almost resemble regular spacing in solar circuits," he said. “We still don't know why they come in clusters or understand how they separate, and we don't know how these regular spacings occur. Every time we answer a question, many more questions arise ”. Yusef-Zadeh and his team still don't know if the filaments move or change over time or what is causing the electrons to accelerate at such incredible speeds. "How do electrons accelerate near the speed of light?" he asked himself. "One idea is that there are some sources at the end of these filaments that are accelerating these particles."

Yusef-Zadeh and his team are currently identifying and cataloging each filament. The angle, curve, magnetic field, spectrum and intensity of each filament will be published in a future study. Understanding these properties will give the astrophysics community more clues to the elusive nature of filaments.