Sunday , July 21 2019
Home / canada / Research: Spinning Black Hole Sprays Light Speed ​​of Plasma into Space –

Research: Spinning Black Hole Sprays Light Speed ​​of Plasma into Space –

Astronomers have discovered fast-moving jets coming out of the black hole nearly 8,000 light-years from Earth.

Posted today in the magazine NatureResearch shows how the V404 Cygni black hole nozzles behave in a way that they have never seen in such a short period of time.

The jets appear to be spinning rapidly with high-speed plasma clouds – potentially just a few minutes apart – firing in a different direction from a black hole.

Associate Professor James Miller-Jones, Curtin University's International Center for Radio Astronomy Research Center (ICRAR), said black holes are some of the most extreme objects in the universe.

"It's one of the most unusual black hole systems I've ever encountered," said Professor Miller-Jones.

"Like many black holes, they feed on a nearby star, pulling gas from the star and forming a disc of material that surrounds a black hole and spirals toward it under gravity."

“What is different from the V404 Cygni is that we think the material disc and the black hole are misaligned. "This seems to cause the inside of the disc to curl like a spinning peak, and the fire will start in different directions because it changes orientation."

V404 Cygni was first identified as a black hole in 1989 when it released a large burst of jets and radiation.

Astronomers looking at archival photographic plates discovered previous explosions in 1938 and 1956 observations.

Professor Miller-Jones said that when the V404 Cygni experienced another very clear explosion in 2015, two weeks ago, telescopes around the world tuned in to studying what was happening.

"They all jumped on any binoculars they could use," he said.

"So we have amazing observation coverage."

When Associate Professor Miller-Jones and his team studied the black hole, they saw her jets behave in a way they had never seen before.

Where it is usually assumed that the nozzles shoot directly from the pole of the black holes, these nozzles fired in different directions at different times.

And they changed direction very quickly – not more than a few hours.

Professor Miller-Jones said the change in nozzle movement is due to the accretion disk – the rotating disk of matter around the black hole.

He said the V440 Cygni's accretion disk was 10 million kilometers wide, and an internal couple of thousand kilometers was inflated and rippled during a bright explosion.

"The inside of the accretion disk was precessing and effectively pulling the nozzles around with it," said Associate Professor Miller-Jones.

"You can imagine it as a rocking peak spinning because it slows down – only in this case is the fluctuation caused by Einstein's theory of general relativity."

The research used observations from the Very Long Baseline Array, a continent-sized radio telescope made up of 10 dishes throughout the United States, from the Virgin Islands in the Caribbean to Hawaii.

Co-author Alex Tetarenko – a recent PhD student at the University of Alberta and currently a colleague working at the East Asian Observatory working in Hawaii – said that the rate at which the jets change meant that scientists had to use a very different approach to most radio observations.

"Typically, radio telescopes produce a single image of several hours of observation," she said.

"But these jets changed so fast that we just saw smudges in the four-hour image.

"It was like trying to take a picture of a waterfall with a shutter speed of one second." Instead, scientists produced 103 individual frames, each 70 seconds long, and merged them into a movie.

"Only then have we been able to see these changes in a very short period of time," said Dr. Tetarenko.

Co-author of Dr. Gemma Anderson, who is also at Curtin University in ICRAR, said the fluctuations in the internal accretion disk could happen in other extreme events in the universe.

"Whenever you get into a mismatch between the spin of a black hole and the material that falls in, you can expect to see it when the black hole begins to feed very quickly," said Dr. Anderson.

"That could include a whole host of other light, explosive events in the universe, such as supermassive black holes that feed very fast, or tide-disrupted events when a black hole tears a star."


Source link