Scientists Discover Vortex Around Black Hole Spinning at 70 Percent the Speed of Light

Astronomers have measured the spin of five supermassive black holes located around 10-11 billion light-years from Earth—and the results reveal that they are moving at staggering speeds.

According to a study published in the Astrophysical Journal, the event horizon of one of these stellar objects is spinning close to or at the speed of light—around 670 million miles per hour. (The event horizon is the point of no return around a black hole past which not even light can escape.)

The four other black holes that the team of astronomers studied appear to be spinning at about half that rate. Furthermore, the scientists found that the vortex of material circling around one of the five black holes is spinning at around 70 percent of the speed of light.

The collection of dust and gas around a black hole—known as an accretion disk—becomes superheated to many millions of degrees as it gradually gets sucked it, generating X-ray light that astronomers can detect using specialized observatories.

The five black holes the team investigated for the latest study have masses between 160 and 500 million times that of our sun. They all are consuming matter from their accretion disk, causing them to grow rapidly.

These types of supermassive black holes that rapidly ingest matter from swirling disks of material—known as quasars—are some of the brightest objects in the universe. However, because the quasars in question are so far away, astronomers made use of a peculiar natural phenomenon known as "gravitational lensing" in order to study them.

Essentially, we can think of gravitational lensing as nature's magnifying glass. With just the right alignment, the immense mass of large objects, such as galaxies, in the intervening space can bend and distort the light coming from even more distant objects directly behind them. This can magnify or produce multiple images of these more distant objects, making them easier to study.

With the help of NASA's Chandra X-ray Observatory, the astronomers used this technique to work out the spin rate of the distant black holes. The astronomers found that the X-rays these quasars are generating are coming from a region of the accretion disk that is only slightly larger than the event horizon itself. As a result, they concluded that the black holes must be spinning extremely rapidly.

These observations are significant because while we have been able to measure the mass of black holes with relative ease in the past, determining their spin rate has proven to be far harder. Such results can help scientists to understand how black holes grow and evolve over time.

"Supermassive black holes have very large masses, ranging from hundreds of millions to billions of solar masses," Xinyu Dai from the University of Oklahoma told Newsweek. "It takes very large amount of energy to spin these supermassive black holes to the near maximal rate. We have previously measured the nearby ones spinning near the maximal rate, and it takes the whole age of the universe to achieve that."

"Here, we observe supermassive black holes back when the universe is quite young, and they are already spinning at the near maximal rate," Dai said. "This suggests that matter falls into black holes in an organized way, rather than randomly during the course of black hole growth."

This article was updated to include comments from Xinyu Dai.

quasar, x-ray
Astronomers have used Chandra to measure the spin of five quasars, each consisting of a supermassive black hole rapidly consuming matter from a surrounding accretion disk. NASA/CXC/Univ. of Oklahoma/X. Dai et al.