Astronomers discover enormous 'barrier' separating the center of the Milky Way from the cosmic ray sea

An artist's impression of the center of the universe. The image is from NASA.

The center of the Milky Way may be more strange than thought.

A team of researchers from the Chinese Academy of Sciences in Nanjing investigated a map of radioactive gamma-rays, the highest-energy form of light in the universe, which can arise when extremely high-speed particles called Cosmic rays crash into ordinary matter.

The map shows that there is a lot of Cosmic rays and gamma-rays just outside the center of the galaxy. The team reported in the journal Nature Communications that something near the core of the Milky Way prevents a large portion of the universe's rays from entering.

The researchers said that the effect is an invisible barrier that is wrapped around the center of the universe and keeping the density of rays there lower than in the rest of the universe. Cosmic rays can get out of the center, but it's hard to get in.

There is a mystery to how this barrier works.

The center of our universe is located in the constellation Sagittarius. It is a dense and dusty place, with more stars than the entire solar system, and wrapped around a black hole with 4 million times the mass of the sun.

The black hole named Sagittarius A*, or perhaps some other object at the center of the universe, is thought to be speeding up protons and electrons to near light speed, creating rays that travel throughout the universe. The high-energy particles created by these rays are roughly the same in density as the rest of the Milky Way. The sea ray is a soup of particles.

The researchers compared the density of rays in the sea to those in the center of the universe. Cosmic rays can't be seen directly, but they can be seen in maps of space, which show where they have collided with other types of matter.

The team used the data from the Large Area Telescope to confirm that something in the center of the universe is shooting particles into the air. Live Science previously reported that Sagittarius A* could theoretically shoot certain particles into space, as black holes could theoretically shoot certain particles into space even as they consume everything else around them.

The barrier is a point on the map where the density of rays drops off at the edge of the center. The source of this phenomenon is difficult to determine, but it may involve the magnetic fields near the dense core.

The team suggested in their paper that dense clouds of dust and gas near the center could collapse onto themselves and cause a magnetic field to be compressed. The stellar winds from the stars at the center may be pushing against the sea.

Further research is needed to figure out what is happening in our universe.

Live Science published the original article.