This composite image, the most detailed to date, shows that these mysterious structures inexplicably suspended in space are ten times more numerous than previously estimated.
These filaments individually span about 150 light-years. They occur in pairs and clusters, often side by side at equal distance, like the strings of a harp.
Professor Farhad Yusef-Zadeh of Northwestern University discovered these structures in the 1980s. The astrophysicist and his colleagues have since established that these filaments are made up of cosmic particles that rotate in the magnetic field at a speed close to that of light, but their origin remained an unsolved mystery.
The new image allows these scientists for the first time to conduct statistical studies on a large population of filaments. This information could help them unravel this long-standing mystery.
We have long studied individual filaments with a myopic point of view, explains in a press release Professor Yusef-Zadeh, main author of the article published in the Astrophysical Journal LettersHave (New window)Have (in English).
” We now have an overview, a panoramic view filled with an abundance of filaments. Before, by analyzing only a few filaments, it was difficult to draw real conclusions about their nature and origin. This is a watershed moment in advancing our understanding of these structures. »
A composite image
Using 200 hours of observing time using the MeerKAT telescope, the team pieced together a mosaic of 20 separate observations of different sections of the sky towards the center of the Milky Way, 25,000 light-years from Earth. .
In addition to the filaments, the image makes it possible to observe the radio emissions of many phenomena, including starbursts, stellar nurseries and the remnants of supernovae.
To visualize the filaments on a finer scale, Prof. Yusef-Zadeh’s team used a technique to remove the background from the main image to isolate the filaments from the surrounding structures.
The resulting image amazed the researchers.
It’s like modern art. She’s so beautiful and so rich, and the mystery of it all makes her even more interesting., enthuses the professor.
Although many mysteries surrounding the filaments remain, Prof. Yusef-Zadeh and his collaborators were able to piece together part of the puzzle. In their paper, they specifically explore the magnetic fields of filaments and the role of cosmic rays in illuminating magnetic fields.
The variation in radiation emitted by the filaments is very different from that of the recently discovered supernova remnant, suggesting that the phenomena have different origins., note the researchers.
They say the filaments are more likely related to past activity of the supermassive black hole Sagittarius A* at the center of the galaxy rather than coordinated supernova explosions.
Also, the filaments could be related to huge bubbles emitting radio waves discovered in 2019 by the same team.
Researchers still continue to wonder about the structure of the filaments. These are separated from each other by perfectly equal distances, roughly the distance between the Earth and the Sun.
They almost look like the regular spacing in sun loops, is surprised Professor Yusef-Zadeh.
” We still don’t know why they come in clusters or how they separate, and we don’t know how these regular spacings occur. Each time we answer a question, others appear. »
The team also needs to figure out if the filaments move or change over time and what causes the electrons to accelerate to such incredible speeds.
For the moment, the researchers are characterizing each filament.
The angle, curve, magnetic field, spectrum and intensity of each filament will be published in a future study, conclude the scientists, who hope that understanding these properties will give astrophysicists new clues about the elusive nature of the filaments.