Astronomers release an improved picture of a black hole: NPR

The researchers used computer simulations of black holes and machine learning to create a revised version (right) of the famous first image of a black hole released back in 2019 (left).

Medeiros et al. 2023

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Medeiros et al. 2023

The researchers used computer simulations of black holes and machine learning to create a revised version (right) of the famous first image of a black hole released back in 2019 (left).

Medeiros et al. 2023

The first iconic image of a black hole looked like a fuzzy orange donut, but now that image has been sharpened into a fiery ring, thanks to computer simulations and machine learning.

The black interior of this ring of hot gases is a region of cosmic weirdness and strong gravity from which nothing, not even light, can escape. It looks much bigger and darker in the upgraded image, according to what’s new a report in Astrophysical Journal Letters.

The image shows the M87 black hole, a supermassive hole about 55 million light-years away that is thought to be 6.5 billion times more massive than the Sun. This is the black hole that was spotted in 2017 by a network of telescopes around the world known as Event Horizon Telescopewhich together served as a giant Earth-sized radio telescope.

Two years later, to great fanfare, the international EHT team announced that they had produced the first image of the M87. says the astrophysicist Lea Medeiros from the Institute for Advanced Study in Princeton, NJ

However, as she says, “We’ll always try to improve and we’ll always try to get an ever better picture.”

The idea of ​​a celestial body with such strong gravity that it would not allow light to escape, rendering it invisible, has been around since the 18th century. Astronomers now know that black holes can form when a dying star collapses in on itself. Although the black hole itself cannot be seen, its existence can be inferred from the effects of its gravity on its surroundings.

For example, gas, dust, and debris that gets pulled into a black hole rotates around it and heats up as it falls inward, creating an outline around the invisible, insatiable monster. This scheme is what the EHT team was able to capture.

This artist’s impression depicts a rapidly spinning supermassive black hole surrounded by a thin disk of spinning material, the remnants of a sun-like star.

ESO, ESA/Hubble, M. Kornmesser/N. Baartmann

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ESO, ESA/Hubble, M. Kornmesser/N. Baartmann

Medeiros explains that making a picture of a black hole with a group of telescopes is very different from taking a picture with an everyday camera. “We don’t take a picture in the sense that, you know, there’s only one camera to click,” she says.

Instead, researchers have to deal with gaps in their data by making certain assumptions and doing a lot of calculations.

In this new version of the image, the gaps have been filled in with the help of physics — namely, computer simulations of black holes — and machine learning. The researchers generated more than 30,000 simulated images of black holes, covering a wide range of possibilities, and then searched for common patterns within those images.

“What we’re really doing is we’re learning the associations between different parts of the image,” Medeiros says. “And so we do that by analyzing tens of thousands of high-resolution images that have been generated from simulations.” “If you have an image, the pixels close to any given pixel are not completely uncorrelated. It’s not that each pixel does completely independent things.”

Learning the connections between the parts of the images, she says, helped them better fill in the gaps created by the missing data. The resulting new image agrees with the old one, but the ring of hot gases orbiting the black hole is noticeably thinner.

“The fact that the ring width is about two times smaller is very exciting,” says Medeiros.

It’s a discovery that will help them understand what happens when matter orbits and falls into a black hole.

“If we have more matter falling into the black hole, it will create a thicker ring. And if we have less matter falling in, it should create a thinner ring, right?” Says.

So far, everything still seems consistent with Albert Einstein’s predictions. This is also true of the only black hole ever imaged, the one at the center of the Milky Way. As noted by this research consortium.

Medeiros believes that continuous improvements in computer software and telescope hardware will improve the image of the M87 black hole more and more.

“In 20 years, the picture may not be the one I show you today,” she says. “It might be better.”