Milky Way Shooting Mystery Gas From The Galactic Center Puzzles Scientists

Researchers discovered the Milky Way shooting a mystery gas from its center. Why it happened remains a mystery but it gives researchers a chance to have a closer look at the phenomenon.

The supermassive black hole at the center of the Milky Way shoots out matter in the form of nuclear galactic wind. "Multiphase" gases have been observed from this flow but the researchers of a new study found evidence of a new mysterious gas shooting out of the galactic center.

Using the Atacama Pathfinder Experiment telescope, the international team found high-velocity clumps of cold molecular gas shooting out of the center of the galaxy "like bullets."

"We've observed there's not only hot gas coming from the center of our galaxy, but also cold and very dense gas," research team member Professor Naomi McClure-Griffiths, of The Australian National University (ANU), said in a news release. "This cold gas is much heavier, so moves around less easily."

This type of cold molecular gas is what stars are typically made of and the researchers found significant amounts of the gas that seems to be mixed with warmer medium. This suggests that the gas is being disrupted.

Although such cold gas clouds have been observed in other galaxies before, those were in galaxies with much bigger black holes and greater star formation activity. This is the first time for such a phenomenon to be observed in the Milky Way.

"The presence of this cold, dense and high-velocity gas is puzzling, because neither Sagittarius A* at its current level of activity nor star formation in the inner Galaxy seems to be a viable source for this material," the researchers wrote.

They said the findings raise questions about what may be happening in the galaxy and how it may affect the future of the galaxy, particularly when it comes to star formation.

"Galaxies can be really good at shooting themselves in the foot," McClure-Griffiths said. "When you drive out a lot of mass, you're losing some of the material that could be used to form stars, and if you lose enough of it, the galaxy can't form stars at all anymore."

The researchers said the amount of the gas being expelled is "not negligible" and may even affect the star formation rate at the central regions of the galaxy.

Although why the galactic center is expelling cold molecular material remains to be a mystery, having it happen closer to home gives researchers a chance to have a much closer look at the phenomenon.

The study is published in the journal Nature.