When it comes to star formation, supermassive black holes are not what springs to mind — rather the opposite. These large cosmic monsters aren’t exactly known for their parenting skills. In fact, they often trigger the early demise of stars by putting an end to their formation.
But not all black holes may be so destructive. In a new paper, scientists describe a black hole that seems to buck the trend and then some. This black hole seems exceptionally nurturing, spreading its stellar progeny throughout its own host galaxy and across multiple other galaxies, some of which are more than one million light-years away.
The black hole may be no exception, scientists say. Instead, these dark voids’ purely destructive reputation may be undeserved.
This is the first time a black hole has been observed to influence star formation in more than one galaxy at a time, dispelling the notion that supermassive black holes always have a negative effect on surrounding stars.
Deep data digging
The findings, published in the journal Astronomy and Astrophysics, stem from x-ray images collected by NASA’s Chandra X-ray Observatory. Chandra captured the radio waves being emitted by the black hole’s high-energy particle jets.
These jets, two narrow beams of hot gas shooting from near the poles of the black hole, swept through the galactic neighborhood. As they hit four surrounding galaxies, star formation accelerated — about two to five times higher than average rates in galaxies of similar masses.
Using a different data set, the scientists found that the black hole’s powerful particle jets extended for one million light-years. That allowed them to trace those emissions to a galaxy located around 9.9 billion light-years away from Earth. Only by combining this data with an optical image from the Hubble Space Telescope and Chandra’s x-ray images did they hit on the black hole’s seemingly unusual influence.
Roberto Gilli, a researcher at the National Institute of Astrophysics in Rome and lead author of the study, tells Inverse that the discovery happened by chance — the researchers just didn’t think it was anything special. How wrong they were.
By taking a similarly detailed approach, the team hope to find more examples of this phenomenon at work in other distant galaxies.
“Black holes probably sometimes can have a positive impact,” Gilli says. “The fact that we don’t know is because of a lack of data.”
Black holes: Not all darkness
But while there are many unanswered questions, the new findings do suggest black holes are not as monolithic as they are made out to be.
“Massive black holes may act as systems that quench star formation, otherwise we would observe many galaxies with a thousand billion solar mass in stars whereas we only see a few,” Gilli says.
Scientists are still not sure how black holes form in the first place, and their origin story, history, and evolution are unclear. All of these factors play into how a black hole behaves within its host galaxy — and how it influences its surroundings. That makes it hard to say anything for certain about these cosmic behemoths, Gillis says.
Until we know where they came from, it would be unfair to judge black holes by their supermassive, eerie void. They may not be as dark as they are made out to be, after all.