Science

Misaligned Black Hole Displays A Unique Behavior

Misaligned Black Hole
Image Credit: ICRAR

Researchers observed a misaligned black hole that is almost 8,000 light-years away from us. They noticed a behavior they’ve never seen in a black hole, which is rapidly swinging plasma jets shooting into space.

The misaligned black hole, called V404 Cygni, is different than other black holes researchers have observed before. The plasma jets it launches occur within minutes of each other and are aimed in various directions. Researchers don’t deny the extreme nature of black holes, but this one is far from typical. They published the results of their study on the black hole in the journal Nature.

“This is one of the most extraordinary black hole systems I’ve ever come across,” study author James Miller-Jones said in a statement.

Miller-Jones is also an associate professor at Curtin University’s International Centre for Radio Astronomy Research.

“Like many black holes, it’s feeding on a nearby star, pulling gas away from the star and forming a disk of material that encircles the black hole and spirals towards it under gravity,” he said. “What’s different in V404 Cygni is that we think the disk of material and the black hole are misaligned. This appears to be causing the inner part of the disk to wobble like a spinning top and fire jets out in different directions as it changes orientation.”

Researchers first observed V404 Cygni in 1989 after spotting the jets and radiation. However, researchers saw the same outbursts in 1938 and 1956 as well, according to archival photographic plates.

What makes this black hole different is that unlike in normal black holes, in which jets shoot out from the poles, V404 Cygni’s jets fire in different directions and at different rates. The change in the directions of the jets is caused by the wobble in part of the black hole’s accretion disk, which was formed from the material of a nearby star that was pulled into the black hole.

Researchers saw that the spinning axis of this black hole is misaligned, which causes an intense wobble, which then causes the jets to be shot in different directions.

“This is the only mechanism we can think of that can explain the rapid precession we see in V404 Cygni,” Miller-Jones said. “You can think of it like the wobble of a spinning top as it slows down, only in this case, the wobble is caused by Einstein’s general theory of relativity.”

Observing the misaligned black hole required researchers to utilize a different method to accurately capture the directions in which the black hole shoots. The researchers had to use a different technique to capture what was happening inside the black hole. Typically, they use long exposures, but with this black hole, they combined 70-second individual exposures to make a film of what was happening.

“These jets were changing so fast that in a four-hour image we saw just a blur,” author and East Asian Observatory Fellow Alex Tetarenko said in a statement.