The black hole in our galaxy is rotating at high speed and dragging space-time with it, according to scientists

(CNN) –A new study has discovered that the massive black hole at the center of our galaxy, Sagittarius A*, is rotating rapidly and changing the spacetime surrounding it.

Space-time is a four-dimensional continuum that describes how we see space, fusing one-dimensional time and three-dimensional space to represent the fabric of space that bends in response to massive celestial bodies.

A team of physicists observed the existing black hole 26,000 light years from Earthwith the observatory Chandra x-ray NASA, a telescope designed to detect X-ray emissions from hot regions of the universe. They calculated Sagittarius A*’s rotation speed using what’s known as the outflow method, which analyzes radio waves and X-ray emissions that can be found in the material and gases surrounding black holes, also known as an accretion disk, according to Stady Published October 21 in Monthly Notices of the Royal Astronomical Society.

The researchers confirmed that the black hole is rotating, generating what is known as the Lens-Thuring effect. Also known as frame drag, this is what happens when a black hole drags on spacetime as it spins. said lead author of the study Ruth Daly.a professor of physics at Pennsylvania State University, who designed Flow method More than a decade ago.

Since inventing the outflow method, Daly has worked on determining the spins of various black holes and has written a book 2019 study Which has explored more than 750 supermassive black holes.

“With this rotation, Sagittarius A* will dramatically change the shape of the spacetime in its surroundings,” Daly said. “We are accustomed to thinking and living in a world in which all spatial dimensions are equal: the distance to the ceiling, the distance to the wall, the distance to the floor… are all linear, and it is not as if one is completely crushed in comparison to others.

“But if you have a rapidly rotating black hole, the spacetime around it is asymmetrical: the rotating black hole pulls all the spacetime with it… It crushes the spacetime, and in some ways it looks like a ball of spacetime.” Football,” he explained.

Space-time disturbance is nothing to worry about, but shedding light on the phenomenon could be very useful for astronomers, Daly said.

“It’s a great tool for understanding the role that black holes play in the formation and evolution of galaxies,” he said. “The fact that they are dynamic entities that can rotate… and therefore can affect the galaxy they are in, is very exciting and very interesting.”

Rotation of supermassive black holes

The black hole’s rotation is assigned a value from 0 to 1, where 0 means that the black hole does not rotate and 1 is the maximum spin value. Previously, there was no consensus on the value of Sagittarius A*’s rotation, Daly said.

According to Daly, using the outflow method, the only method that uses information from both the outflow and material near the black hole, Sagittarius A* was discovered to have a rotational angular momentum value between 0.84 and 0.96. while M87*Black hole Virgo galaxy group It is 55 million light-years from Earth, has a rotation value of 1 (with a large uncertainty of plus or minus 0.2), which is close to its mass limit.

While the team discovered that the two black holes were rotating at similar speeds, M87* is much larger than Sagittarius A*, Daly said, so Sagittarius A* has less distance to travel and rotates more times per revolution than M87*.

Sagittarius A* “spins much faster (in comparison), not because it has higher rotational angular momentum, but because it has less distance to travel when it spins,” Daly explained.

Black holes and galactic history

Daly said that knowing the mass and rotation of the black hole helps astronomers understand how it forms and evolves.

He said that black holes formed as a result of the merger of smaller black holes usually have a low spin value. Dejan Stojkovic, a professor of cosmology at the University of Buffalo, who was not involved in the study. However, the black hole formed with the accretion of surrounding gas will have a high spin value.

He noted that the speed at which Sagittarius A* rotates indicates that a significant portion of the black hole’s mass comes from accretion.

“The question of whether or not the central black hole in our galaxy is rotating, or at what speed it is rotating, is very important,” Stojkovic said in an email.

“Ultimately, we want to measure the properties of the center of our galaxy in the best way possible. This way we can learn about the history and structure of our galaxy, test our theories, or even infer the existence of some very interesting objects such as wormholes,” added Stojkovic, lead author of the paper. 2019 study On virtual structures.