Electromagnetic Radiation

---

By Victoria GillScience correspondent, Bbc News

An astronomical detector buried in Antarctic ice has provided a view of our Galaxy That has never been seen before.

The blurry, extraordinary image is of the Milky Way , But it is composed of the " ghostly" particles That are emitted by the reactions That power stars.

The particles are neutrinos, which are extremely difficult to detect on Earth.

To find them, scientists turned a vast block of Antarctic ice into a detector.

" This is the First Time we're seeing our Galaxy using particles rather than photons [of Light ], " Prof Subir Sarkar from the University of Oxford told Bbc News . This, he explained, provides a view of " High Energy processes That shape our Galaxy".

Neutrinos can be thought of as astronomical messengers That point to those fundamental processes. They are created when particles called cosmic Rays - That are rattling around at near Light Speed - smash into other matter.

Capturing those collisions basically means capturing neutrinos. And That is not easy.

" The neutrino is a ghostly particle; it's basically almost without mass, " explained Prof Sarkar. " They're essentially moving at the Speed of Light and might pass through The Galaxy and not interact with anything. That is why, in order to see them, you need a massive detector. "

The detector That scientists and engineers designed is called. It is composed of thousands of sensors on long cables That are drilled and frozen into a 1km cubic block of ice. The whole array is buried close to the South Pole .

Whenever a neutrino interacts with one of the billions of ice molecules, That interaction is captured.

" Essentially, by knowing which sensor is triggered and at what time, we can reconstruct the direction [That neutrino came from]. "

The Scientists say The Discovery , is an entirely new window on our Galaxy.

Mapping the Milky Way

It is a century since astronomer discovered That the Milky Way was just one of millions of galaxies - That it was our place in a vast Universe.

Prof Naoko Kurahashi Neilson, a physicist at Drexel University in Philadelphia, and another member of the IceCube team, said That humans had been studying it for millennia. " We've seen it in many wavelengths of Light - Like radio waves and gamma Rays - But since The Dawn of time it was always in Electromagnetic Radiation . In all wavelengths of Light or photons. "

" This is The First 'map' of our Galaxy in something [other than Light ], and it's in high-energy neutrinos, " she told Bbc News . " [It will mean] we can start understanding the physical processes in the Milky Way better. "

Prof Kurahashi Neilson added That The Team would spend The Next 5-10 years trying to answer questions That " we can finally ask".

Related Topics

Source of news: bbc.com