Last week, scientists presented an image of a supermassive black hole burping—twice. The behemoth had guzzled on gas before belching out a cloud of high-energy particles and settling in for a few thousand years' nap. Then it woke up and did the whole thing again. Eat, sleep, repeat.
But why do black holes burp, and what can this tell scientists?
High-Energy Particles
Intense gravitational and magnetic forces surround black holes. These can pull in large amounts of matter, creating a veil of dust and gas. As the greedy black hole feasts on this nearby gas, some is expelled in a powerful kind of burp. Each "burp" is really an outflow of high-energy particles, which astronomers can observe using X-ray images.
Double Belch
Scientists have seen black holes burp like this before. What's special about this new image is the fact it reveals two belches. About 100,000 years after the first burp, the black hole, which sits in the J1354 galaxy 800 million light years away, spewed out a second.
This confirms that black holes can turn their power output on and off in a relatively short space of time. Although 100,000 years might seem long, in cosmological terms it is minute, given that the universe itself began 13.8 billion years ago.
"We are seeing this object feast, burp, and nap, and then feast and burp once again, which theory had predicted," said Julie Comerford of the University of Colorado, who led the study, in a statement.
The information has big implications for physics. Repeated burps had been predicted, but this is the first time more than one has been observed from the same black hole.
By analyzing the area around the black hole, the scientists were also able to narrow in on the cause of this second belch. The researchers believe that a nearby galaxy collision sent clumps of gas swirling toward the black hole. Just like its first meal, the black hole ate, belched and then napped.
A Gassy Milky Way
The research suggests the supermassive black hole in our own galaxy could also burp repeatedly. It has belched at least once before and is currently lying in wait of another big feast.
University of Colorado postdoctoral fellow Scott Barrows says: "Our galaxy's supermassive black hole is now napping after a big meal, just like J1354's black hole has in the past. So we also expect our massive black hole to feast again, just as J1354's has."
This research was presented last week at the American Astronomical Society's annual meeting in Washington, D.C., and published in The Astrophysical Journal.
