This image shows the jet in the M87 galaxy in polarized light, as captured by ALMA. Related: Images: Black holes of the universe The polarized image we see tells us about the structure and strength of these magnetic fields very close to the black hole in M87, where the jet is launched," Dexter said. "Astronomers have long thought that magnetic fields carried by the hot gas near black holes play an important role in letting the gas fall in, and in launching relativistic jets of energetic particles out into the surrounding galaxy. The team's observations and this new view of the object in M87 is deepening scientists' understanding of the structure of magnetic fields just outside of a black hole, as it has remained a mystery how jets larger than the galaxy itself are emitted from the black hole at its heart. "These polarized receivers work in a way similar to that of the polarized sunglasses that some people use."īy showing the black hole in M87 through polarized light, the team got a better look at the object's event horizon, which is also known as the "point of no return" because it's the point at which no matter can get closer to the black hole without being pulled in. They also were able to better study the interaction with the object's accretion disk, which is a disk of hot gas and other diffuse material that falls in toward a black hole and swirls around it. "The radio telescopes of the EHT have receivers that record the sky signal in polarized light," Ivan Marti-Vidal, also a coordinator of the EHT Polarimetry Working Group and GenT Distinguished Researcher at the Universitat de Valencia in Spain, told. The team is also working on making a video showing how Sgr A* changes over time.To capture the black hole, the collaboration used eight telescopes from around the world, combining their power to create a virtual Earth-sized telescope (the EHT). Three telescopes were added to the EHT network before the most recent observing campaign in March 2022, which means future pictures should be sharper and should illuminate subtle details in the areas around black holes. It isn’t clear why there is this mismatch in the spin axes of the black hole and the Milky Way, but it could be related to ancient events in which Sgr A* may have devoured black holes at the centres of smaller galaxies.Īs researchers continue to analyse the black hole data and figure out how the two black holes compare to one another, they also have a new set of observations to examine. Instead of viewing the black hole and its disc from the side, we appear to be viewing it face-on. The only thing that doesn’t line up with what was expected is that the accretion disc around Sgr A* appears to be tilted out of alignment with the disc of the galaxy. “Einstein’s doing well, again, and for people who have all their other theories of what gravity could be it might be a little disappointing.” “One of the things which surprises me personally was just how similar these images are to what theory predicts,” says Younsi. When the researchers compared the image of Sgr A* to a library of hundreds of thousands of simulated black holes modelled in scenarios that do not follow general relativity, they found that Sgr A* appears to hew closely to relativistic models. The gravitational pull of Sgr A* is so strong that it bends the light, making the plasma circling towards us appear brighter than that spinning away towards the black hole’s backside. The most visible prediction of general relativity is that the ring of light around the black hole ought to be a little lopsided. This makes them impossible to see directly, and so astronomers have had to use a variety of clever techniques to confirm that they actually exist. To make the final image, they aggregated many snapshots taken over several nights and used a supercomputer to process the data.īlack holes are objects with an intense gravitational pull so strong that not even beams of light, the fastest things in the universe, can escape. “This means the brightness and pattern of the gas around Sgr A* was changing rapidly as the EHT collaboration was observing it – a bit like trying to take a clear picture of a puppy quickly chasing its tail,” said EHT researcher Chi-kwan Chan at the University of Arizona in a statement.Īdding to the difficulty was the fact that Earth sits towards the edge of the Milky Way, so the researchers had to deal with light from all the stars, dust and gas between our planet and Sgr A*. As a result, it takes days to weeks for the plasma around M87* to complete an orbit, whereas it takes only minutes for hot plasma to circle Sgr A*. M87* is one of the largest known black holes in the universe at about 6.5 billion times the mass of the sun, more than 1000 times the mass of Sgr A*. That process occurs much more quickly with this black hole than with M87*, which is one reason why the new image took so much longer to produce.
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