Unusual Black Hole Activity, First of its Kind Seen

Astronomers have been able to identify some unusual activity coming from a black hole not too far away from Earth. This supermassive black hole appears to have started emitting a stream of gas, providing new insight into how black holes act and interact with their surroundings.

Initially, the international astronomy team that made this discovery didn't know what they were looking at. According to a study published ahead of print in the journal Science Express, the researchers had been in the midst of an intensive galaxy observation campaign using data from a total of six different NASA and ESO telescopes and unmanned spacecraft. They had just turned their attention to NGC 5584 - a galaxy 244.6 million light years from Earth - when something didn't look right.

"The data represented dramatic changes since the last observation with Hubble in 2011," study author Gerard Kriss of the Space Telescope Science Institute said in a statement. "I saw signatures of much colder gas than was present before, indicating that the wind had cooled down due to a significant decrease in X-ray radiation from the galaxy's nucleus."

NGC 5584 has a supermassive and incredibly dense black hole at its center - something not uncommon among large galaxies.

Interestingly, the unusual gas emission from this kind of black hole was a new kind of sight. Blazars, galaxies literally powered by incredibly immense black holes, are known for firing awe-inspiring jets of gas and radiation. These concentrated jets of fast moving gas, however, never move, and remain parallel to the disk-shape of the galaxy it fires from.

NGC 5584 is doing no such thing. Instead it's firing a weaker stream of incredibly fast moving gas (up to 3,107 miles per second) within the galaxy itself and in no set direction.

"There are other galaxies with similar streams of gas flowing outward from the direction of its central black hole, but we've never before found evidence that the stream of gas changed its position as dramatically as this one has," Kriss said.

According to Kriss, the only reason his team was even able to stumble upon this unusual phenomenon was because the gas stream just happened to aim Earth's way, suddenly blocking 90 percent of NGC 5584's emitted X-rays.

"This is the first time we've seen a stream like this move into our line of sight. We got lucky," he said.

The study detailing this discovery was published in Science Express on June 19.