New view of our galaxy’s black gap reveals a swirling magnetic area

That is the supermassive black gap on the centre of our galaxy as we’ve by no means seen it earlier than. The picture reveals the swirling magnetic fields round Sagittarius A* (Sgr A*) and hints that it might be producing a jet of high-energy materials, which astronomers have but to see.

The image was taken by a community of observatories world wide working as a single, big telescope, referred to as the Occasion Horizon Telescope (EHT). In 2022, it produced the primary picture of Sgr A*, revealing mild coming from whirling sizzling plasma set towards the darkish background of the black gap’s occasion horizon, the place mild can’t escape its excessive gravity.

Now, EHT researcher Ziri Younsi at College Faculty London and his colleagues have measured how this mild is polarised, or the orientation of its electromagnetic area, displaying the path and energy of the magnetic area round Sgr A*.

The picture is remarkably much like the magnetic area of M87*, the primary black gap EHT studied. On condition that M87* is round 1500 instances extra huge than Sgr A*, it means that supermassive black holes could have related buildings no matter their dimension, says Younsi.

One main distinction between M87* and our galaxy’s black gap is the dearth of seen high-energy jets seen from Sgr A*. This absence has lengthy puzzled astronomers, however the truth that Sgr A* has a magnetic area like M87* means that there could possibly be jets in our galaxy’s black gap, too.

“There’s this actually thrilling trace that there could also be some extra construction,” says Younsi. “There is likely to be one thing occurring that’s fairly thrilling within the centre of the galaxy, and I feel that these outcomes we’re going to want to comply with up.”

This may make sense given different items of proof we see for a jet that will have existed way back in our galaxy’s historical past, such because the Fermi bubbles, massive spheres of X-ray-producing plasma above and under the Milky Approach.

In addition to revealing a possible hidden jet, the magnetic area’s properties may assist clear up different astrophysical mysteries, reminiscent of how particles like cosmic rays and neutrinos are accelerated to extraordinarily excessive energies, says Younsi. “The magnetic fields are the bedrock of all of this. Something which provides us extra perception into how black holes and magnetic fields work together is simply foundationally essential for astrophysics.”

Younsi and his colleagues hope to take extra pictures of Sgr A* with a bigger community of telescopes and extra superior tools, which can enhance their understanding of the character of the magnetic area and the way it is likely to be producing jets. The EHT will start these observations in April, though the info is prone to take a number of years to course of.

References: The Astrophysical Journal Letters, DOI: 10.3847/2041-8213/ad2df0 & DOI: 10.3847/2041-8213/ad2df1