After capturing the first photo of a black hole, the Event Horizon telescope zooms in for a second

Do all black holes work the same, regardless of their size?

We tend to think of black holes as gargantuan, light-eating behemoths. But even supermassive black holes, the gravitational sinkholes that exist at the center of galaxies, come in a range of sizes. Take M87 *, which is in the center of the Messier 87 galaxy. It is about 6 billion times more massive than our sun. Or you can watch Sgr A *, which sits at the center of the Milky Way and is only (only!) 4 million times more massive than the sun. Small, as far as supermassive black holes are concerned.

The incredible size of M87 * was part of the reason it was such a good candidate for the Event Horizon Telescope to capture the world’s first image of a black hole. This feat, achieved in 2017, was immediately hailed as a breakthrough in astrophysics when it was revealed to the world in 2019. The portrait was the culmination of years of work using a handful of observatories around the world that were essentially functioning like one planet. – telescope size. The breakthrough allowed scientists to see the shadow cast by the dark heart of Messier 87.

But that was just the start.

Astrophysicists weren’t going to stop at a single black hole. They then turned their attention to another supermassive black hole, about 100 times smaller than M87 *, located in the center of the nearby galaxy known as Centaurus A. Using the same technique that captured M87 *, astrophysicists have now been able to image a powerful jet of matter moving away from the Centaur A black hole in ultra-high resolution, revealing more about how these puzzling phenomena emerge.

The details were published Monday in the journal Nature Astronomy.

“The main purpose of the EHT is to image black holes,” says Michael Janssen, an astrophysicist at the Max Planck Institute for Radio Astronomy in Bonn, Germany, and lead author of the study. “But the jets are naturally launched by the black holes that we are studying. So, to fully understand black holes, we also need to understand these jets and how they are produced.”

Cosmic jets are produced by many black holes – including M87 * – and are essentially leaking plasma freight trains launched by the accretion disk of a rapidly spinning black hole.

“These narrow, focused plasma beams carry energy at small scales close to the black hole (which is smaller in size than our solar system) and deposit them in the environment at much larger scales,” explains James Miller-Jones, astrophysicist at Curtin University in Australia and member of the International Center for Research in Radio Astronomy (ICRAR). The jets, according to Miller-Jones, can affect the evolution of the galaxy and the galaxy cluster – so astronomers want to better understand them.

Janssen and his colleagues are one of these groups of astronomers. They wanted to zoom in on the jets to see how they functioned near the black hole. The EHT made it possible.

The EHT is made up of eight observatories from around the world and uses a technique known as Very Long Baseline Interferometry, or VLBI. As a rule, Janssen notes, larger telescopes provide sharper images, but there isn’t enough size to build them. Instead of building a monolithic telescope, the EHT virtually connects telescopes around the world, delivering resolution equivalent to that of a single telescope “several thousand miles away.”

Thanks to him, the team could focus on Centaurus A’s throw and see it more clearly than ever before. It also allowed them to image the jet extremely close to the black hole.

“We are able to study this jet with a resolution lower than daylight, which has never been achieved before,” said Janssen. The EHT observations allow the team to see about 0.6 light days from the black hole – which looks tiny but is roughly 2.5 times the distance between the sun and Pluto, a 9.6 billion sloth. kilometers.

Examining the core of Centaurus A and comparing their observations with theoretical models, the team found that the black hole jet had thinned edges and surprisingly resembled the one created by M87 *. This is essential because it brings us back to our original question: do all black holes work the same, regardless of their size?

The Centaurus A jet suggests that this could be the case. This is important for two reasons: it is consistent with Albert Einstein’s theory of general relativity, and it is “the rationale that the fundamental properties of jets depend on the mass of the black hole that launches them,” says Miller-Jones.

He adds that this scaling could then be valid for much, much smaller black holes, with masses only 10 to 100 times that of the sun. We can’t prove these little black holes because they’re too small – but by studying their monstrous cousins, we unravel some of the mysteries of the universe’s most enigmatic giants.