Polski
русский
Українська

First image of "ghost particles" in the Milky Way galaxy: IceCube detector finds neutrinos

Dmytro IvancheskulLife
The unique IceCube detector helped catch neutrinos from the Milky Way galactic plane. Source: IceCube Collaboration/US National Science Foundation/ESO/OBOZREVATEL collage

Astronomers have made a real breakthrough by detecting high-energy neutrinos along the galactic plane, or Milky Way band, in the night sky for the first time in history. The high-energy neutrinos, which have millions and billions of neutrino energy produced by the thermonuclear reactions that power stars, were detected by the IceCube neutrino observatory, a gigaton detector operating at the South Polar Station.

Scientists reported the findings in the "Science" journal. Neutrinos are subatomic particles that move at the speed of light and have no mass.

The IceCube is a one-of-a-kind detector that covers a cubic kilometer of deep Antarctic ice, equipped with more than 5,000 light sensors. It captures signs of high-energy neutrinos originating from our galaxy and beyond, all the way to the farthest reaches of the universe. The detector monitors the unique bursts of light that occur on rare occasions when neutrinos crash into atoms.

"The capabilities of the highly sensitive IceCube detector, combined with new data analysis tools, have given us a whole new perspective on our galaxy, one that previously could only be hinted at," said Denise Caldwell, director of physics at the US National Science Foundation.

Neutrinos are very hard to find because they rarely collide with atoms. A light-year thick lead will only stop about half of the neutrinos flying through it. This explains why neutrinos are called "ghost particles."

Neutrinos are produced by radioactive decay occurring in nuclear reactors, or when extremely high-energy particles hit atoms. The most lively types of neutrinos have energies millions and billions times higher than those produced in the fusion reactions that power stars.

 

High-energy neutrinos are known to originate from galaxies outside the Milky Way. But researchers have long suspected that our own galaxy is also their source. For example, when cosmic rays— atomic nuclei moving nearly at the speed of light-—hit dust and gas, they generate both gamma rays and high-energy neutrinos.

Previous studies have detected gamma rays from the plane of the Milky Way, so scientists expected high-energy neutrinos from there as well. There have been hints of such radiation, but this is the first time scientists have been able to record the phenomenon.

The research team focused on the plane of the Milky Way, a dense region of the galaxy lying along the Milky Way's equator. They examined 10 years of IceCube data, analyzing 60,000 neutrinos -- 30 times more than previous neutrino scans of the galactic plane.

In their study, the scientists also used artificial intelligence technology, which helped them isolate neutrinos coming from long distances from the neutrino background produced by cosmic ray collisions with molecules in Earth's atmosphere.

Eventually, they were able to detect high-energy neutrinos that probably came from the galactic plane of the Milky Way.

"This observation of high-energy neutrinos opens a whole new window for studying the properties of our galaxy," Space.com quoted the study's co-author, astroparticle physicist Mirko Huennefeld of Dortmund University of Technology in Germany.

He said the results helped scientists achieve "a new milestone in neutrino astronomy."

Although the results suggest that the newly found neutrinos come from our galaxy, IceCube is not yet sensitive enough to pinpoint their sources. According to Huennefeld, they may appear diffusely, or a significant number may come from certain points in the sky.

As the scientist noted, in the coming years IceCube will receive an upgrade of the detector, "which will further increase its sensitivity, which will allow us to get a clearer picture of the Milky Way in neutrinos in the near future."

Earlier OBOZREVATEL also told that scientists for the first time saw a paired suicide of stars that they could not even imagine.

Subscribe to OBOZREVATEL channels in Telegram and Viber to keep up with the latest developments.

Other News