High in the mountains of Mexico, an international team of researchers has made an exciting discovery at the center of our galaxy.
Using the High-Altitude Water Cherenkov (HAWC) observatory, located 13,000 feet above sea level on the Sierra Negra volcano, scientists have detected ultrahigh-energy gamma rays coming from the Milky Way’s core.
These gamma rays carry over 100 teraelectron volts of energy, which is ten times more than any previously observed from that region.
“This is a glimpse into the Milky Way’s core at much higher energy levels than ever seen before,” said Pat Harding, a physicist at Los Alamos National Laboratory and principal investigator on the project.
The findings confirm the existence of a mysterious source called a PeVatron at the center of our galaxy.
This discovery indicates that some of the most extreme and powerful processes in the universe are taking place in this region, known as the Galactic Center Ridge.
The HAWC observatory has been collecting data for over seven years. During this time, researchers recorded nearly 100 gamma-ray events with energy levels surpassing 100 teraelectron volts.
By analyzing this data, they can now study how cosmic rays interact with the PeVatron source and pinpoint its location right at the heart of the Milky Way.
A PeVatron is a powerful cosmic source that can accelerate particles to extremely high energies, reaching a million billion electron volts (PeV).
This level of energy is far greater than the particles emitted by ordinary light bulbs. These cosmic rays travel close to the speed of light, interacting with the dense gas clouds near the galactic center, and produce the ultrahigh-energy gamma rays detected by HAWC.
The PeVatron remains somewhat of a mystery. Scientists speculate that it could be linked to highly violent events, such as supernovas (exploding stars), or perhaps the collisions of black holes or neutron stars.
However, such extreme events are rare in our galaxy, making it surprising to find a PeVatron so close to home.
The HAWC observatory is specially designed to detect these rare gamma rays. It consists of 300 large tanks filled with water, each equipped with light detectors at the bottom. When gamma rays reach Earth’s atmosphere, they create showers of smaller particles.
As these particles pass through the tanks faster than light can move through water, they produce a blue glow called Cherenkov radiation—similar to the sound of a sonic boom but with light.
This discovery builds on previous work by the Milagro observatory, which operated in the Jemez Mountains of New Mexico until 2008.
With the success of HAWC, the research team is now planning a new experiment called the Southern Wide-field Gamma-ray Observatory. It will be built in Chile’s Atacama Desert to get an even clearer view of the galactic center and solve more mysteries of the Milky Way.
This groundbreaking research offers a fascinating glimpse into one of the most powerful places in our galaxy, deepening our understanding of the forces at work in the universe.
