Astronomers find evidence of wind coming from the Milky Way’s black hole

Soon, the The central black hole of the Milky Way it’s starting to look a little weirdo.

Astronomers have discovered a large cone-shaped gap in the surrounding gas Sagittarius A*a giant galaxy a black holewhich may solve a long-standing mystery.

All active black holes must blow winds or jets of material back to space while eating, in theory. That process is how supermassive black holes shape the galaxies around them. But no matter how hard astronomers look, they’ve never seen our black hole, called Sgr A* for short, throwing anything back out.

New images from a team of researchers led by Northwestern University now suggest that this giant moving through a cloud of cold gas is evidence of that missing wind. It was probably an arrow headed back toward the black hole, said Mark Gorski, who led the study.

“This is the first time we’ve had a clear enough view to see the effect of wind,” Gorski said in a statement. statement. “We looked at the data and said, ‘Here it is. There’s something that everybody’s been looking for for 50 years.’

In fact, the discovery wasn’t exactly an a-ha moment. Only after the team has covered its image with data does it appear NASAChandra’s Chandra X-ray Observatory made what they saw start to make sense. That gave them confidence that the strange cone was more than just a metaphor, they said.

“When you find something that no one has seen before, the first thought that comes to your mind is not ‘Oh my God, we found it,'” producer Elena Murchikova said in a statement. “Oh my God, what happened to my analysis?”

Scientists believe almost all large galaxies have a giant black hole at their core. These are regions millions to millions of times larger than the sun. In fact, so much mass is packed into these tiny spaces that gravity is strong enough to prevent anything from escaping – even light.

These black holes don’t just sit around, waiting for gas, dust, and stars to fall in, but they influence the way their galaxies evolve by absorbing material and ejecting material that approaches their boundary— called the event horizon – go back.

By taking high-resolution observations with Large Atacama Millimeter/Submillimeter Array in Chile in about five years, the team was able to map the cold gas near the black hole in unprecedented detail. This ALMA image is 100 times deeper and 80 times sharper than previous maps, according to the researchers.

The cone extends from one to three light-years away from the black hole. A simple explanation after careful consideration, according to group findings published in The Astrophysical Journal Lettersthat a fast, powerful stream of hot matter exited the black hole’s surface, ejecting cold gas in its path.

The ALMA radio telescopes in Chile have spent five years observing the central part of the Milky Way to create high-resolution maps of the cold gas surrounding it.
Credit: ALMA /S. Longmore et al. / ESO / D. Minniti et al.

The team determined that it would take more energy than all the stars in that area to form a conic gap. Researchers estimate that the wind has probably been blowing for 20,000 years or more.

Based on the image, the surface of Sgr A*’s atmosphere appears tilted and uneven, suggesting that it may be weakened and compressed by the surrounding gas as it moves.

How this feature escaped the notice of previous researchers is not too surprising, the researchers said. To see our galactic centerastronomers must look to the plane of the Milky Way, which is thick with gas, dust, and ionized structures. Sgr A* may also be quiet, making distant activity difficult to see.

Some scientists have suggested that the lack of wind or jets could mean that Sgr A* is an extraterrestrial black hole – one out of the billions of others like it. If anything, Murchikova is now convinced of the opposite.

“It shows that our black hole is not unique, and our place in space is not unique,” he said.