The turbulent heart of the Milky Way contains nearly 1,000 inexplicable magnetic filaments — ten times more than previously thought — a new image has revealed.
The strange spatial strands, some of which stretch up to 150 light-years across, were first discovered by astronomers at Northwestern University back in the early 1980s.
Radio waves were used to observe the filaments. They appear in clusters and pairs, some even being spaced like strings on an instrument.
The team believe that filaments are comprised of cosmic ray electrons gyrating the magnetic field at close to the speed of light — but their origins remain a mystery.
The researchers stated that they will be able to do statistical studies on a wider range of strings in order to solve the puzzle.
The team have already ruled out supernovae as the source of the filaments — and suspect they may have been created by our galaxy’s supermassive black hole.
The turbulent heart of the Milky Way contains nearly 1,000 inexplicable magnetic filaments — ten times more than previously thought — a new image (pictured) has revealed
Pictured is a mosaic view of the Milky Way heart. These filaments are visible as vertical slashes across the galaxy.
Observations using radio waves have shown the filaments to be highly organised, appearing in pairs and clusters, with some evenly spaced out like strings on a harp — as pictured
The study was conducted by Northwestern University astrophysicist Farhad Yusef-Zadeh — who spotted the first strands back in 1984 — and his colleagues.
We have been looking at individual filaments over a period of time and had a limited view. Just examining a few filaments makes it difficult to draw any real conclusion about what they are and where they came from,’ explained Professor Yusef-Zadeh.
‘Now, we finally see the big picture — a panoramic view filled with an abundance of filaments. This represents a major breakthrough in understanding these structures.
“This is the first study of statistical properties of filaments. “By studying statistics we can learn more information about the properties these uncommon sources,” the astrophysicist stated.
“If you are from another planet and meet one tall individual on Earth, it is possible to assume that all humans are the same height. However, if statistics are done across the entire population, it is possible to find the average height.
‘That’s exactly what we’re doing. It is possible to determine the strength, length, orientation, and spectrum of electromagnetic fields.
The new image of the Milky Way’s centre was the result of three years’ worth of sky surveys undertaken using the MeerKAT radio telescope at the South African Radio Astronomy Observatory (SARAO) in the country’s Northern Cape providence.
After a total of 200 hours of telescope time, the team were able to piece together a mosaic of 20 separate observation of different parts of the sky in the direction of the galactic centre — which lies some 25,000 light years from Earth.
Alongside the filaments, the final composite image also captures numerous other sources of radio emissions — including outbursts from stars, stellar nurseries and new supernova remnants.
Ian Heywood of Oxford University, paper author and astrophysicist, stated that he spent much time staring at the image while working on the project.
“When I show the image to people new to radio astronomy […]Radio imaging isn’t always done this way. MeerKAT has made great strides in radio imaging capabilities.
“It was a privilege to have worked over the years alongside colleagues from SARAO, who created this incredible telescope.”
Some of the strange spatial strands shown in this photo, which can stretch 150 light-years wide, were originally discovered by Northwestern University’s astronomers back in 1980.
This new view of the Milky Way’s central point was created by three years worth of sky observations using the MeerKAT radiotelescope (pictured at South African Radio Astronomy Observatory’s Northern Cape provisionnce).
To get a clearer look at the filaments, the team used a special technique that allowed them to remove the background from the main image — isolating the strands.
“It’s almost like modern art.” These images are so beautiful and rich, and the mystery of it all makes it even more interesting,’ said Professor Yusef-Zadeh.
The researchers said that they are particularly intrigued by how structured the filaments appear — with those in clusters seemingly spaced at equal intervals, each around the distance of that from the Earth to the sun.
Professor YusefZadeh said, “They nearly resemble the regular spacing of solar loops.”
‘We still don’t know why they come in clusters or understand how they separate and we don’t know how these regular spacings happen.
“Every time you answer one question, many other questions will arise.”
Such question, for example, include whether or not the filaments change over time, or move — and what is causing the electrons to accelerate in the first place.
How can electrons be accelerated at the speed of light? Professor Yusef Zadeh was intrigued.
It is possible that some filaments have sources which accelerate these particles.
After a total of 200 hours of telescope time, the team were able to piece together a mosaic of 20 separate observation of different parts of the sky in the direction of the galactic centre — which lies some 25,000 light years from Earth. Pictured: the distribution of the strengths of magnetic fields in the final, composite image of the heart of the Milky Way
To get a clearer look at the filaments, the team used a special technique that allowed them to remove the background from the main image — isolating the strands, as pictured
With this latest study complete, the researchers are now working to identify and catalogue each filament in the image — noting its orientation, curve, magnetic field, spectrum and intensity, properties that may shine a light on the strands’ nature.
“We are certain that we’re one step closer toward a deeper understanding. Science is not a linear progression on many levels,” stated Professor YusefZadeh.
“We hope to understand it better, but we need more observation and theory. Complex objects require time to fully understand.
A pre-print of the researchers’ article, which has not yet been peer-reviewed, can be read on the arXiv repository — as can an accompany paper presenting the full image created from the MeerKAT data.
The two articles have been accepted for publication in The Astrophysical Journal Letters and The Astrophysical Journal, respectively.
Three years of sky surveying at South Africa’s Northern Cape providednce with the MeerKAT radio telescope, resulted in the new view of the Milky Way’s center.