Milky Way's black hole 'exhaust vent' discovered in eerie X-ray observations

The monster black hole at the center of our galaxy may be unleashing huge, gassy explosions — and now, astronomers think they've pinpointed the exact spot where that superheated gas is spilling into the Milky Way.

Acting like a gargantuan exhaust vent, the newly discovered feature is a bright region of X-ray energy that's nearly 700 light-years from the galaxy's supermassive black hole but linked to it by a long "chimney" of superhot gas. 

According to new research accepted for publication in The Astrophysical Journal, this spray of X-rays results from hot, black-hole-driven gas Traveling up the chimney and colliding with cooler gas in the surrounding environment at more than 2 million mph (3.2 million km/h), sending enormous shock waves rippling through the galaxy.

The discovery could unlock secrets about the supermassive black hole's eating habits — and help reveal the true nature of some of the most Mysterious objects lurking in the galactic center.

"Astrophysicists have long been interested in the movement of material and energy from the Milky Way's center and its black hole, both to understand what's happening in our cosmic backyard and how galaxies form and evolve," lead study author Scott Mackey, an astrophysicist at the University of Chicago, said in a statement. "We're really excited to find this new piece of the puzzle."

Black hole belches

The Milky Way's supermassive black hole, Sagittarius A* (Sgr A*), is roughly 4 million times more massive than the sun. It sits at the dense, chaotic center of our galaxy, steadily gobbling up hapless stars, gas clouds and other matter that gets too close to its event horizon — the point beyond which nothing, not even light, can escape.

But infalling matter doesn't always make it into our black hole's maw. Sometimes, matter gets channeled by powerful magnetic fields into jets that spew away from the black hole at high speeds. In 2019, astronomers spotted evidence of our black hole's messy eating habits when they detected two huge chimneys — one towering above Sgr A* and one descending below — siphoning hot gas away from the galactic center for hundreds of light-years in each direction.