NASA reveals an 'energy trap' at the center of our galaxy

NASA reveals an 'energy trap' at the center of our galaxy

Scientists have discovered a ‘trap’ at the center of the Milky Way that could be capturing high-energy cosmic rays.

These particles travel at nearly the speed of light, and are thought to have been produced outside of the galactic center before being slowed by gas clouds.

The phenomenon was spotted using data from NASA’s Fermi Gamma-ray Space Telescope and the High Energy Stereoscopic System (HESS), and according to the researchers, this region may concentrate some of the fastest particles in the galaxy.

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Scientists have discovered a ‘trap’ at the center of the Milky Way that could be capturing high-energy cosmic rays. The phenomenon was spotted using data from NASA’s Fermi Gamma-ray Space Telescope and the High Energy Stereoscopic System (HESS). The Milky Way is pictured

WHAT ARE COSMIC RAYS? 

A long-standing puzzle in astrophysics is the source of ultra-high-energy particles from space that hit Earth.

Called cosmic rays, they're up to a billion times more energetic than particles at Cern's Large Hadron Collider.

They strike the atmosphere and cause an enormous shower of other particles, mostly muons, electrons and photons, over a wide area.

Though they were discovered decades ago, cosmic rays at these high energies are very rare, making it difficult to pinpoint where in the universe they originated.

It's thought that some come from supernovae, but it's likely there are other sources of cosmic rays in the universe as well.

‘Our results suggest that most of the cosmic rays populating the innermost region of our galaxy, and especially the most energetic ones, are produced in active regions beyond the galactic center and later slowed there through interactions with gas clouds,’ said lead author Danielle Gaggero at the University of Amsterdam.

‘Those interactions produce much of the gamma-ray emission observed by Fermi and HESS.’

According to the researchers, roughly 90 percent of cosmic rays are protons.

The rest are made up of electrons and the nuclei of atoms.

As they move through space, the magnetic fields disrupt their paths, making it difficult to pinpoint their origins.

But, the researchers say the interactions between cosmic ways and matter can offer further clues about them.

These interactions result in the emission of gamma rays, the highest-energy form of light, according to NASA.

Observations by the HESS Collaboration in 2016 revealed a glow of gamma rays reaching nearly 50 trillion electron volts (TeV).

This is about 50 times greater than the energies observed by Fermi’s Large Area Telescope.

HESS, a ground-based observatory, can spot emissions once the atmosphere absorbs gamma rays, sending particles out in a flash of blue light.

Fermi, on the other hand, detects the rays when they enter the telescope.

In the new study, the researchers combined the two types of observations, revealing a continuous gamma-ray spectrum for the galactic center emission.

Observations by the HESS Collaboration in 2016 revealed a glow of gamma rays reaching nearly 50 trillion electron volts (TeV). This is about 50 times greater than the energies observed by Fermi’s Large Area Telescope. The HESS observatory is shown 

‘Once we subtracted bright point sources, we found good agreement between the LAT and LESS data, which was somewhat surprising due to the different energy windows and observing techniques used,’ said co-author Marco Taoso at the Institute of Theoretical Physics in Madrid and Italy’s National Institute of Nuclear Physics in Turin.

According to the researchers, this suggests the same cosmic rays found elsewhere in the galaxy are responsible for the gamma rays seen at the center.

But here, the highest energy particles move less efficiently.

‘The most energetic co smic rays spend more time in the central part of the galaxy than previously thought, so they make a stronger impression in gamma rays,’ said co-author Alfredo Urbano at the European Organization for Nuclear Research in Geneva and INFN Trieste.

While this effect is not shown in the conventional models of cosmic ray movement, the researchers say simulations incorporating it have better agreement with the Fermi observations.

‘The same breakneck particle collision responsible for producing these gamma rays should also produce neutrinos, the fastest, lightest, and least understood fundamental particles,’ said co-author Antonio Marinelli of IFN Pisa.

The findings could help to explain phenomena seen in other studies as well, the researches say. 

‘Experiments like IceCube in Antarctica are detecting high-energy neutrinos from beyond our solar system, but pinpointing their sources is much more difficult,’ said Regina Caputo, a Fermi team member at NASA’s Goddarg Space Flight Center, who was not involved in the study.

‘The findings from Fermi and HESS suggest the galactic center could be detected as a strong neutrino source in the near future, and that’s very exciting.’ 

 

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