In the middle of a galaxy more than 2 billion light years from Earth, a black hole called PDS-456 spews radiation and ultra-fast winds. The gusts carry more energy per second than a trillion suns and blow outward in all directions at intensities high enough to stop stars from forming, pitting the galaxy in a huge, cosmic struggle with the mysterious force at its center.
It may sound like something from science fiction, but the phenomenon has been quantified for the first time by researchers at NASA and the European Space Agency.
In a study published in the journal Science on Friday, astronomers say they have calculated the speed, shape and size of the winds surrounding black holes, allowing them to figure out how these forces impact their galaxies.
Contrary to popular depictions, black holes aren’t dark vortices of empty space. Rather, they are extremely dense collections of matter formed when stars collapse on themselves. Their gravitational pull is so strong that nothing, not even light, can escape.
Astronomers have long understood that black holes have an impact on the galaxies that surround them. Looking at galaxies is the only way they can even study the phenomena, since black holes can’t be directly observed. Past research shows that galaxies with large black holes will have a similarly large “bulge” at their center.
But this new study demonstrates that the high-speed winds surrounding black holes, called quasar winds, also affect their galaxies. The winds intensify in proportion with the black hole’s growth, pushing gas outward.
“Now we know quasar winds significantly contribute to mass loss in a galaxy, driving out its supply of gas, which is fuel for star formation,” lead author Emanuele Nardini said in a NASA press release.
Scientists think that a black hole and its galaxy are engaged in a kind of astronomical balancing act — as a galaxy expands, the black hole at its center works to impede the growth and prevent new stars from developing.
The study, which uses data from NASA’s Nuclear Spectroscopic Telescope Array and the ESA’s XMM-Newton telescope, also gave scientists a better understanding of the behavior of quasar winds. Rather than emanating from a black hole in a single direction, the winds emerge from it in a spherical blast.
PDS-456, the black hole at the center of this study, is a unique phenomenon in astronomy: close enough to Earth for a good look, but also unlike other bodies in our cosmic neighborhood. It’s a rare “supermassive black hole” — something much more common 10 billion years ago, not long after the beginning of the universe.
“For an astronomer, studying PDS-456 is like a paleontologist being given a living dinosaur today,” co-author Daniel Stern said.