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Found: Milky Way black hole’s missing wind

The half-century-long search is finally over, opening a new window into the physics at play in the center of the galaxy

June 4, 2026

This composite image shows evidence for a wind blowing away from Sagittarius A* (Sgr A*), the supermassive black hole in the center of our galaxy. The white dot in the center of the image shows Sgr A*. In orange is data from the Atacama Large Millimeter/Submillimeter Array radio telescopes in Chile, mapping the location of cold gas composed of carbon monoxide in the image. In blue is X-ray data from NASA’s Chandra X-ray Observatory. Image by NASA/CXC/Northwestern University/Mark Gorski

Space

Weinberg College

The hunt is over.

After more than 50 years of searching, astrophysicists at Northwestern University have finally discovered evidence of a powerful wind blowing from the Milky Way’s central supermassive black hole, Sagittarius A* (Sgr A*).

According to theoretical physics and a long-accepted understanding of galaxies evolution, as black holes consume materials, they should produce wind or jets. Even a small amount of gas falling into a black hole should generate enough energy to push material outwards. Without wind, Sgr A* would be a unique outlier.

But, until now, no one could find it.

By providing the most detailed view yet of how Sgr A* interacts with and transforms its surrounding environment, the scientists resolved one of the longest-standing mysteries in astronomy. It also opens a new window into the physics at play in the center of the Milky Way.

The study was published in The Astrophysical Journal Letters.

“Unless a black hole exists in a perfect vacuum, it must blow a wind somehow,” said Northwestern’s Mark Gorski, who co-led the study. “And there is no perfect vacuum in the universe. With new observations, this is the first time we’ve had a clean enough view to see the wind’s imprint. We looked at the data and said, ‘There it is. There is the thing that everybody’s been looking for for 50 years.’”

“We were the first to show that molecular gas very, very close to the black hole is feeding it,” said Elena Murchikova, who co-led the study with Gorski. “The wind is not powerful, and its direction probably wanders with time. It shows that our black hole is not unique, and our place in the universe is not unique.”

Focused on the evolution of galaxies, Gorski is a research assistant professor at Northwestern’s Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA). An expert on black hole astrophysics, Murchikova is an assistant professor of physics and astronomy at Northwestern’s Weinberg College of Arts and Sciences and member of CIERA.

Elusive wind at the galaxy’s heart

Although black holes are infamous for swallowing anything that ventures too close, they don’t just pull matter in. They also push material out. For decades, theorists have predicted that all actively feeding black holes launch powerful outflows. As material spirals inward toward a black hole, it moves faster and faster — until it reaches close to the speed of light. This creates enough energy and pressure to fling some of the hot, fast-moving material outward in the form of winds or jets.

While astronomers have spotted evidence of past eruptions from Sgr A*, they struggled to detect currently occurring outflows. The Northwestern team says this is likely because Sgr A* is in a quieter phase and just incredibly difficult to see.

“To observe our own black hole, we have to look through the plane of our galaxy,” Murchikova said. “That means we have to peer through gas, dust and ionized structures, and you can’t really see through all of that easily.”

A cone-shaped cavity

Now, with new tools and observations, the team finally was able to take a closer look. Using five years of extraordinarily deep observations from the Atacama Large Millimeter/Submillimeter Array (ALMA) radio telescopes in Chile, Gorski and Murchikova constructed the sharpest image ever devised of cold molecular gas surrounding the black hole.

The image reflected the gas located incredibly close to Sgr A* — within just one parsec (or about three light-years) of the black hole. Then, the duo applied a calibration method to remove the black hole’s bright radio signals. The resulting image is 100 times deeper and 80 times sharper than previous maps of the region. With this level of detail, it revealed structures that were completely invisible in previous observations.

But one newly revealed, unmistakable feature left Gorski and Murchikova gobsmacked. A vast, cone-shaped cavity — nearly one parsec long and 45 degrees wide — was devoid of cold molecular gas. According to the researchers, only hot, energetic wind blowing from Sgr A* could have created this...