Skip to main content

Machine learning used to sharpen the first image of a black hole

The world watched in delight when scientists revealed the first-ever image of a black hole in 2019, showing the huge black hole at the center of galaxy Messier 87. Now, that image has been refined and sharpened using machine learning techniques. The approach, called PRIMO or principal-component interferometric modeling, was developed by some of the same researchers that worked on the original Event Horizon Telescope project that took the photo of the black hole.

That image combined data from seven radio telescopes around the globe which worked together to form a virtual Earth-sized array. While that approach was amazingly effective at seeing such a distant object located 55 million light-years away, it did mean that there were some gaps in the original data. The new machine learning approach has been used to fill in those gaps, which allows for a more sharp and more precise final image.

A team of researchers, including an astronomer with NSF’s NOIRLab, has developed a new machine-learning technique to enhance the fidelity and sharpness of radio interferometry images. To demonstrate the power of their new approach, which is called PRIMO, the team created a new, high-fidelity version of the iconic Event Horizon Telescope's image of the supermassive black hole at the center of Messier 87, a giant elliptical galaxy located 55 million light-years from Earth. The image of the M87 supermassive black hole originally published by the EHT collaboration in 2019 (left); and a new image generated by the PRIMO algorithm using the same data set (right).
The image of the M87 supermassive black hole originally published by the Event Horizon Telescope collaboration in 2019 (left); and a new image generated by the PRIMO algorithm using the same data set (right). L. Medeiros (Institute for Advanced Study), D. Psaltis (Georgia Tech), T. Lauer (NSF’s NOIRLab), and F. Ozel (Georgia Tech)

“With our new machine-learning technique, PRIMO, we were able to achieve the maximum resolution of the current array,” said lead author of the research, Lia Medeiros of the Institute for Advanced Study, in a statement. “Since we cannot study black holes up close, the detail in an image plays a critical role in our ability to understand its behavior. The width of the ring in the image is now smaller by about a factor of two, which will be a powerful constraint for our theoretical models and tests of gravity.”

Recommended Videos

PRIMO was trained using tens of thousands of example images which were created from simulations of gas accreting onto a black hole. By analyzing the pictures that resulted from these simulations for patterns, PRIMO was able to refine the data for the EHT image. The plan is that the same technique can be used for future observations from the EHT collaboration as well.

“PRIMO is a new approach to the difficult task of constructing images from EHT observations,” said another of the researchers, Tod Lauer of NSF’s NOIRLab. “It provides a way to compensate for the missing information about the object being observed, which is required to generate the image that would have been seen using a single gigantic radio telescope the size of the Earth.”

In 2022, the EHT collaboration followed up its image of the black hole in M87 with a stunning image of the black hole at the heart of the Milky Way, so that image could be the next target for sharpening using this technique.

“The 2019 image was just the beginning,” said Medeiros. “If a picture is worth a thousand words, the data underlying that image have many more stories to tell. PRIMO will continue to be a critical tool in extracting such insights.”

The research is published in The Astrophysical Journal Letters.

Georgina Torbet
Georgina has been the space writer at Digital Trends space writer for six years, covering human space exploration, planetary…
Biggest stellar black hole to date discovered in our galaxy
Astronomers have found the most massive stellar black hole in our galaxy, thanks to the wobbling motion it induces on a companion star. This artist’s impression shows the orbits of both the star and the black hole, dubbed Gaia BH3, around their common centre of mass. This wobbling was measured over several years with the European Space Agency’s Gaia mission. Additional data from other telescopes, including ESO’s Very Large Telescope in Chile, confirmed that the mass of this black hole is 33 times that of our Sun. The chemical composition of the companion star suggests that the black hole was formed after the collapse of a massive star with very few heavy elements, or metals, as predicted by theory.

Black holes generally come in two sizes: big and really big. As they are so dense, they are measured in terms of mass rather than size, and astronomers call these two groups of stellar mass black holes (as in, equivalent to the mass of the sun) and supermassive black holes. Why there are hardly any intermediate-mass black holes is an ongoing question in astronomy research, and the most massive stellar mass black holes known in our galaxy tend to be up to 20 times the mass of the sun. Recently, though, astronomers have discovered a much larger stellar mass black hole that weighs 33 times the mass of the sun.

Not only is this new discovery the most massive stellar black hole discovered in our galaxy to date but it is also surprisingly close to us. Located just 2,000 light-years away, it is one of the closest known black holes to Earth.

Read more
Stunning image shows the magnetic fields of our galaxy’s supermassive black hole
The Event Horizon Telescope (EHT) collaboration, who produced the first ever image of our Milky Way black hole released in 2022, has captured a new view of the massive object at the center of our Galaxy: how it looks in polarized light. This is the first time astronomers have been able to measure polarization, a signature of magnetic fields, this close to the edge of Sagittarius A*. This image shows the polarized view of the Milky Way black hole. The lines mark the orientation of polarization, which is related to the magnetic field around the shadow of the black hole.

The Event Horizon Telescope collaboration, the group that took the historic first-ever image of a black hole, is back with a new stunning black hole image. This one shows the magnetic fields twirling around the supermassive black hole at the heart of our galaxy, Sagittarius A*.

Black holes are hard to image because they swallow anything that comes close to them, even light, due to their immensely powerful gravity. However, that doesn't mean they are invisible. The black hole itself can't be seen, but the swirling matter around the event horizon's edges glows brightly enough to be imaged. This new image takes advantage of a feature of light called polarization, revealing the powerful magnetic fields that twirl around the enormous black hole.

Read more
Nightmare black hole is the brightest object in the universe
Artist’s impression showing the record-breaking quasar J059-4351.

A  recently discovered monster black hole feasts on so much nearby material that it's the fastest-growing of its kind on record. The beefy black hole is devouring the equivalent mass of our sun every single day, making it a record-breaker in more ways than one.

“The incredible rate of growth also means a huge release of light and heat,” said lead researcher Christian Wolf of The Australian National University in a statement. “So, this is also the most luminous known object in the universe. It’s 500 trillion times brighter than our sun.”

Read more