There’s a ‘trap’ at the centre of our galaxy, chock-full of gamma rays

19 Jul 2017

The Milky Way. Image: Avigator Thailand/Shutterstock

The very centre of the Milky Way is awash with action, according to the latest study from NASA scientists.

Some of the fastest particles in our galaxy are stored at the centre of the Milky Way, with high-energy cosmic rays caught in a ‘trap’.

With the innermost region of our galaxy in focus, NASA thinks it is here where the most extreme activity is underway.

Future Human

Researchers found a diffuse glow of gamma rays reaching nearly 50trn electron volts (TeV) last year.

To put these numbers in perspective, the energy of visible light ranges from about two to three electron volts.

Strong core

The most recent study shows 1,000 TeV, observed at the galactic centre. These particles move through the region pretty inefficiently, leaving more of a trail for researchers to observe.

“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 centre and later slowed there through interactions with gas clouds,” said lead author Daniele Gaggero at the University of Amsterdam.

Antonio Marinelli of INFN Pisa, co-author of the paper, said the “breakneck particle collisions” that result in these gamma rays may also produce the fastest, lightest and least understood fundamental particles: neutrinos.

This is of keen interest due to the mystique behind them.

For example, in 2015, Takaaki Kajita and Arthur McDonald won the Nobel Prize in Physics “for the discovery of neutrino oscillations, which shows that neutrinos have mass”.


This metamorphosis proves that neutrinos must have mass, completely changing our understanding of how the universe is made up.

Neutrinos travel straight to us from their sources because they barely interact with other matter and carry no electrical charge, so magnetic fields don’t sway them.

Meanwhile, yesterday (18 July), NASA released a soundtrack from waves of electrons rippling through space.

In the example below, we can hear ‘chorus’ radio waves from within Earth’s atmosphere – captured by instruments aboard NASA’s Van Allen Probes – which are created when electrons are pushed towards the night side of our planet.

Gordon Hunt was a journalist with Silicon Republic