According to a new study using data from NASA’s Chandra X-ray Observatory and the US National Space Agency, the supermassive black hole at the center of the Milky Way is spinning so fast that it is warping the space-time around it. Turning into what might look like a football. Carl G. Jansky of the Science Foundation Very Large Array (VLA). This football shape shows that the black hole is spinning at a considerable speed, which the researchers estimate is about 60 percent of its possible range.

The work, led by Penn State Berks Professor of Physics Ruth Daly, was published. Monthly Notices of the Royal Astronomical Society.

Astronomers call this giant black hole Sagittarius A* (Sgr A*). It is located about 26,000 light-years from Earth in the center of the galaxy. To determine how fast Sgr A* is rotating — one of its main characteristics, along with mass — the researchers used a method that uses X-ray and radio data. To estimate how material is flowing towards and away from the black hole. This method was developed and published by Daily in 2019. The Astrophysical Journal.

“Our work could help resolve the question of how fast our galaxy’s supermassive black hole is spinning,” Daly said. “Our results suggest that Sgr A* is rotating very rapidly, which is interesting and has far-reaching implications.”

The team found the angular velocity — the number of rotations per second — to be about 60% of the maximum possible value of Sgr A*’s spin, a limit set because the material does not travel faster than the speed of light. can

Past estimates of the speed of Sgr A* have been made by various techniques and other astronomers, with results ranging from no rotation at all to rotation at a near-maximal rate.

“This work, however, shows that this may change if the amount of material surrounding Sgr A* increases,” Daley said.

As a black hole spins, it pulls in “spacetime” — the sum of time and the three dimensions of space — and nearby matter. Gravity also squashes spacetime, changing its shape depending on how it is observed. If a black hole is viewed from above, spacetime appears circular. However, by the way, spacetime is shaped like a football. The faster the spin, the flatter the football.

Spin can also act as a source of energy, Daley said, if matter — such as gas or the remnants of a star that orbits too close — exists around the black hole. As the black hole rotates, matter can be ejected in narrow jets called collimated outflows. However, Sgr A* is currently constrained by nearby matter, so the black hole has remained relatively quiet in recent centuries, with weakly accreted outflows.

“A spinning black hole is like a rocket on a launch pad,” said co-author Bunny Sebastian of the University of Manitoba in Winnipeg, Canada. “Once the material gets close enough, it’s as if someone fueled the rocket and hit the ‘launch’ button.”

This means that in the future, if the properties of matter and the strength of the magnetic field near the black hole change, a fraction of the energy of the black hole’s spin could lead to a more powerful emission. This source material could come from gas or from the remnants of a star that has been torn apart by the gravity of a black hole if that star strays too close to Sgr A*.

“Coherent jets driven by a galaxy’s rotating central black hole can profoundly affect the supply of gas to the entire galaxy, which in turn affects how much gas is produced,” said co-author Megan Donahue of Michigan State University. how quickly and even what stars can form,” said co-author Megan Donahue from Michigan State University. “The ‘Fermi bubbles’ seen in X-rays and gamma rays around our Milky Way’s black hole show that the black hole may have been active in the past. Measuring the rotation of our black hole is an important test of this scenario. “

Fermi bubbles refer to structures that emit gamma rays above and below a black hole that researchers have previously theorized to result from mass ejections.

The researchers used the exclusion method to determine the spin of Sgr A*. Daly’s approach includes consideration of the relationship between a black hole’s spin and its mass, the properties of matter near the black hole, and the properties of the emission. The collimated outflow produces radio waves, while the disk of gas around the black hole emits X-rays. The researchers combined observational data from Chandra and the VLA with independent estimates of the black hole’s mass from other telescopes to inform the ejection mechanism and determine the black hole’s spin.

“We have a special view of Sgr A* because it is the closest supermassive black hole to us,” said co-author Annan Lu from McGill University in Montreal, Canada. “Although it’s quiet right now, our work shows that in the future it will deliver an incredibly powerful kick to the surrounding matter. It could happen in a thousand or a million years, or it could happen in our lifetimes. can.”

In addition to the above, co-authors include Christopher O’Dea, University of Manitoba, and Daryl Haggard, McGill University.

NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts and flight operations from Burlington, Massachusetts.