An artist’s composition of the Milky Way seen with a neutrino lens (blue).
Astronomers are hailing a “new lens” they can use to observe the universe after the publishing of this new image (above) of our Milky Way galaxy.
Instead of light, the image uses particles called neutrinos—a fundamental sub-atomic particle that has a very small mass. It’s an entirely new view of our galaxy.
Huge Step
Published today in the journal Science, the IceCube Collaboration—an international group of over 350 scientists using the IceCube Neutrino Observatory gigaton detector in Antarctica—has found evidence of high-energy neutrino emission from the Milky Way.
“Observing our own galaxy for the first time using particles instead of light is a huge step,” said Naoko Kurahashi Neilson, professor of physics at Drexel University, IceCube member, and Sclafani’s advisor. “As neutrino astronomy evolves, we will get a new lens with which to observe the universe.”
A view of the IceCube Lab with a starry night sky showing the Milky Way and green auroras.
Cosmic Rays
When cosmic rays interact with the dust and gas in the Milky Way, gamma rays and neutrinos are produced. Astronomers have measured the former before and in 2022 detected high-energy neutrino emission coming from the M77 galaxy.
The weak interaction of neutrinos with matter and radiation makes their detection extremely difficult. The IceCube Neutrino Observatory has over 5,000 sensors in a cubic kilometer of ice that search for signs of high-energy neutrinos originating from our galaxy and beyond. Detected neutrinos produce faint patterns of light when they interact with the ice, some of which can be traced back to their source in the sky.
The breakthrough is a result of upgrades to the IceCube detector and new machine learning data analysis tools, which enabled the scientists to find the source of neutrinos detected over the last decade.
Hidden Features
The dataset used in the study included 60,000 neutrinos spanning 10 years of IceCube data. That’s 30 times more events that any previous study has used.
The result was an image of the Milky Way showing bright spots where gamma rays had been observed where cosmic rays had collided with interstellar gas—a presumed source of neutrinos.
“A neutrino counterpart has now been measured, thus confirming what we know about our galaxy and cosmic ray sources,” said Steve Sclafani, a physics PhD student at Drexel University, IceCube member and co-lead analyzer.
“As these capabilities continue to be refined, we can look forward to watching this picture emerge with ever-increasing resolution, potentially revealing hidden features of our galaxy never before seen by humanity,” said Denise Caldwell, director of National Science Foundation’s Physics Division.
Wishing you clear skies and wide eyes.
