Scientists snap first photo of two black holes in an epic staredown

Astronomers have captured a radio image showing two black holes orbiting each other for the first time, just six years after the publication of the first-ever photo of a single black hole.

The discovery confirms that pairs of supermassive black holes actually exist – something scientists have suspected for decades but never seen directly until now.

The system is at the heart of a brilliant space object called quasar OJ 287, approximately 3.5 billion light years of the Earth. Quasarsa portmanteau for “quasi-stellar objects,” are extremely bright galactic cores powered by black holes feasting on surrounding gas and dust. OJ 287 has long stood out because its brightness increases and decreases every 12 years. This pattern was a clue that two giant black holes could rotate around each other like a cosmic do-si-do.

The new observations are among the most precise radio images ever taken to explore what’s happening deep inside a quasar – and offer evidence that the two black holes could produce their own powerful jets of energy.

“The image of the two black holes was captured with a radio telescope system including the RadioAstron satellite,” said Mauri Valtonen of the University of Turku in Finland, in a declaration. “In recent years, we have only been able to use ground-based telescopes, where the image resolution is not as good.”

Black holes are among the most mind-boggling objects in the cosmos. These are regions of space where gravity is so intense that nothing, not even light, can escape. About 50 years ago, astronomers weren’t entirely convinced that these invisible giants actually existed.

Today, black holes are not only accepted, they are photographed by a collection of enormous synchronized satellite dishes. In 2019, the Event Horizon telescope produced the first ever image of a black holelocated 53 million light years away in the galaxy Messier87. Three years later, the same group captured another historic image: the black hole at the center of our own Milky Way, called Sagittarius A*or Sgr A* for short.

This new historic radio image is part of a broader framework OJ 287 study directed by Valtonen, who appears in The Journal of Astrophysics. The host galaxy is thought to have a huge black hole – about 18 billion times the weight of the Universe. sun – and a smaller companion with a mass of about 150 million suns. As the smaller orbits, it periodically crashes through the larger black hole’s disk of gas and dust, creating predictable bursts of light.

The first clues that something strange was happening in OJ 287 appeared in the late 1800s, according to the paper, when the quasar appeared unexpectedly in early photographs of the sky — long before scientists even realized it. black holes existed.

In the 1980s, Finnish astronomer Aimo Sillanpää noticed its repeating light pattern and proposed the idea of ​​two black holes. Since then, researchers around the world have tracked the system, trying to map the couple’s movement. More recently, scientists have calculated how they think the pair should appear.

The black hole at the center of the Milky Way, Sagittarius A*, was photographed with the Event Horizon Telescope, a virtual telescope the size of Earth.
Credit: Collaboration with the Event Horizon telescope

Confirmation of this duo came from a powerful network of radio telescopes that included Russia’s RadioAstron satellite, which operated until 2019. Its antenna once orbited about 120,000 miles from Earth, about halfway through Earth’s orbit. moon. When combined with ground-based satellite dishes, this configuration achieves extremely high resolution.

The approach differed from how previous images of black holes had been made, which used the Event Horizon Telescope, a virtual Earth-sized telescope that links radio antennas around the world. Instead, the new OJ 287 image used a space-based technique that “allowed for a much longer observational baseline, and therefore a higher resolution image,” said Daniel Reichart, a professor at the University of North Carolina and one of the study’s co-authors.

The method has its drawbacks: It uses longer radio wavelengths that become blurred as they travel through space, making it impossible to see the edge of a black hole. The tradeoff, Reichart told Mashable, is that the Event Horizon Telescope “has slightly lower resolution, but higher fidelity,” providing clearer images. But using space technology, the team was able to see enough detail to separate the two black holes within OJ 287. Without this resolution, the pair would otherwise appear as a single light.

“For the first time, we managed to obtain an image of two black holes rotating around each other,” Valtonen said. “Black holes themselves are perfectly black, but they can be detected by these jets of particles or by the glowing gas surrounding the hole.”

The team also saw something new: a spinning jet coming from the smaller black hole, which appears to move back and forth as it moves through its orbit. Future studies could observe a change in jet direction over time.