A view of the Milky Way supermassive black hole in polarised light. Image: EHT Collaboration
Scientists say that these fields bear a ‘striking’ resemblance to those around the black hole in the centre of another distant galaxy, M87.
Scientists have unveiled a new image taken by the Event Horizon Telescope (EHT) that appears to show “strong and organised” magnetic fields spiralling out of the black hole in the centre of the Milky Way galaxy.
According to the European Southern Observatory (ESO), this is the first time the magnetic fields have been seen in polarised light. The image of the magnetic field structure bears a strong resemblance to that of the black hole at the centre of M87, which was the first ever black hole to be photographed back in 2019.
“What we’re seeing now is that there are strong, twisted and organised magnetic fields near the black hole at the centre of the Milky Way galaxy,” said Dr Sara Issaoun, a NASA Hubble Fellowship Programme Einstein Fellow and co-lead of the project.
“Along with Sgr A [Sagittarius A, the black hole in the centre of our galaxy] having a strikingly similar polarisation structure to that seen in the much larger and more powerful M87 black hole, we’ve learned that strong and ordered magnetic fields are critical to how black holes interact with the gas and matter around them.”
Situated roughly 27,000 light years away from Earth, the supermassive black hole in the centre of the Milky Way is more than a thousand times smaller and less massive than the one in the centre of M87. Owning to the “striking” resemblance, scientists wondered if the two black holes – arguably the most mysterious objects in the observable universe – share other common traits.
3/ The results are strikingly similar to those the EHT already obtained for the much larger & powerful #BlackHole at the centre of the M87 galaxy, suggesting that strong magnetic fields may be common to all black holes.
The two black holes side-by-side 👇
📷 EHT Collaboration pic.twitter.com/8GlPPXAUju
— ESO (@ESO) March 27, 2024
The ESO said that previous studies of light around the M87 black hole revealed that the magnetic fields around it allowed the black hole to launch “powerful jets of material” back into the surrounding environment. Now, the latest images have revealed the same may be true for our very own black hole.
“By imaging polarised light from hot glowing gas near black holes, we are directly inferring the structure and strength of the magnetic fields that thread the flow of gas and matter that the black hole feeds on and ejects,” said Dr Angelo Ricarte, Harvard Black Hole Initiative Fellow and project co-lead.
“Polarised light teaches us a lot more about the astrophysics, the properties of the gas, and mechanisms that take place as a black hole feeds.”
To make this observation of Sgr A possible, the team of scientists linked eight telescopes around the world – known collectively as the EHT – to create a virtual Earth-sized telescope. Two of these telescopes are associated with the ESO and situated in the Atacama Desert in Chile.
“As the largest and most powerful of the telescopes in the EHT, ALMA [Atacama Large Millimeter/submillimeter Array] played a key role in making this image possible,” said Dr María Díaz Trigo of the ESO.
“ALMA is now planning an ‘extreme makeover’, the Wideband Sensitivity Upgrade, which will make ALMA even more sensitive and keep it a fundamental player in future EHT observations of Sgr A and other black holes.”
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