The second, in a pre-print study soon to be published in the Astrophysical Journal, is the discovery of an astrophysical jet from a supermassive black hole 12.7 billion light-years away and more than a billion times more massive than the sun, discovered for the first time in 2018. The team used NASA’s Chandra X -ray Observatory, which searches for x-ray emissions from very hot objects in the universe, to make these observations. It is the most distant astrophysical jet ever observed with x-rays.
Each set of discoveries breaks some esoteric astronomical record, but that’s not why they’re important. Both help explain why supermassive black holes are able to grow so quickly even though they are constantly releasing high-energy matter. What the team found is the first such evidence that the jets to encourage rapid feeding of a black hole.
In the first investigation, after Magellan confirmed the existence of the black hole, the team used other instruments, such as the Very Large Telescope in Chile, to discern other properties of the black hole and its jet, like the mass.
The additional data shows how the jets encourage feeding. The black hole’s intense gravitational force attempts to pull massive amounts of gas and dust into its event horizon (the point of no return). This material has angular momentum, which means it doesn’t just drop straight, it circles the event horizon. Meanwhile, the radiation pressure in the area (created by friction and stress in the orbiting disc of matter heating up until it glows) continues to push the gas away from the event horizon.
What’s going on is a bit complex, but essentially the jet’s highly energized particle beam takes away the angular momentum of the gas as it travels outward. And unlike radiation pressure, which shines and pushes in all directions, the jet is narrow and therefore barely able to interact and affect the less dense gas layers farther away. With a way for the gas to lose angular momentum with little recoil, much of the gas surrounding the event horizon simply falls off.
“In this way, the jet ensures that the black hole is not actively working against itself – it is able to continue to feed,” says Thomas Connor, NASA astronomer and co-author of the two articles. Although scientists suspected that the jets might play a role in encouraging the feeding process, “so far we haven’t really seen convincing evidence on this,” he says.
X-ray study reinforces this idea. These observations revealed that the jet traveled 150,000 light years from its source, making it the first X-ray observation of jets more than a few thousand light years away. “This large-scale x-ray detection means we’ve been using these jets for incredibly long periods of time,” says Connor. These aren’t just transient blips, but they have lasted for hundreds of thousands of years – long enough to help a supermassive black hole feed and grow very quickly. “We now know that this is a long term process, and this is how these jets are actually able to help these supermassive black holes build up,” he says. “It’s the missing piece that connects 15 years of theory to our current situation.”
Both studies help lay the groundwork for follow-up results that could help us learn more about how supermassive black holes evolved and helped shape the early universe. We now have a better idea of how to search for black holes from those ancient times, as well as the understanding that more x-ray observations could be essential in learning how jet feed dynamics work.
For Connor, those additional observations will be key. And he’s pretty encouraged after this week’s punch. The discovery “indicates that there are a lot more of these objects out there,” he says, “and hopefully we can break the distance record again soon enough.