Dark matter discovery: Scientists hoping to find the mysterious substance by following gamma rays

A new study revealed that dark matter in the universe can be discovered by tracing the origins of gamma rays

By Carlo Inigo Monzon
January 23, 2020 15:20 +08

How does it look when earth is bombarded with dark matter?

A new study explained how scientists were able to come up with a way that could possibly help detect dark matter. As explained by the scientists, tracking gamma rays can help uncover this mysterious cosmic substance.

According to scientists, dark matter is an invisible substance in space that is believed to make up over 80 percent of the universe's mass. As for gamma rays, these are high-energy light bursts produced by powerful objects in space such as black holes and supernovae.

Large galaxy clusters contain both dark matter and normal matter. The immense gravity of all this material warps the space around the cluster, causing the light from objects located behind the cluster to be distorted and magnified. This phenomenon is called gravitational lensing. This sketch shows paths of light from a distant galaxy that is being gravitationally lensed by a foreground cluster. NASA & ESA

Tracking Gamma Rays In Space

Gamma rays are technically invisible to the human eye. But, through special telescopes, astronomers are able to spot them and trace them back to their point of origin. Although most gamma rays originate from known cosmic events, astronomers have come across faint emissions from unidentified sources.

In a new study submitted for publication to the Physical Review Letters, a group of scientists investigated the unknown origins of these faint gamma rays. After comparing them with maps of gamma rays with known origins, or those that come from supernova and stellar collision events, the scientists discovered that the anomalous gamma rays came from parts of the universe that are known to be rich in dark matter.

These images show the steadily improving view of the Moon’s gamma-ray glow from NASA’s Fermi Gamma-ray Space Telescope. Each 5-by-5-degree image is centered on the Moon and shows gamma rays with energies above 31 million electron volts, or tens of millions of times that of visible light. At these energies, the Moon is actually brighter than the Sun. Brighter colors indicate greater numbers of gamma rays. This image sequence shows how longer exposure, ranging from two to 128 months (10.7 years), improved the view. NASA/DOE/Fermi LAT Collaboration

Hunting For Dark Matter

As explained by the scientists, dark matter is known to self-destruct. This can either happen by natural decaying or by colliding with other dark matter particles. In these scenarios, the destruction of dark matter can produce gamma rays.

"Dark matter could decay like a radioactive nucleus, producing gamma rays as it does," astrophysicist Daniel Gruen, the co-author of the study, told Live Science. "Or perhaps multiple dark matter particles are colliding, producing gamma-rays as they interact."

By tracking the origins of the unknown and faint gamma rays, the scientists are hoping to discover dark matter or at least traces of it. If all goes well for the team, the scientists will be able to provide an effective method for tracking dark matter. The results of their study will also allow other scientists to learn more about the properties of dark matter particles and how they interact with their surroundings.