Sunday , July 25 2021

The supermassive black hole of our galaxy can point to us a relativistic jet



Things are officially exciting. The new science has just come from cooperating to shoot Sagittarius A *, the super massive black hole in the center of the Milky Way, and reveals secrets in the dusty heart of our galaxy.

The picture below is the best shot of Sgr A * (do not worry, there is still something to come from the Event Horizon telescope), and although it may seem like a strange light to you, astrophysicists studying radio data can learn a lot of what they are watching – and they think they have identified a relativistic jet directed at the Earth.

Since the image taken from the region is the highest resolution – twice as high as the previous one – the researchers are able to accurately accurateize the light characteristics around the black hole scattered by the cloud.

"The galactic center is full of matter around the black hole that acts as frosted glass, which we have to look at," said astrophysicist Eduardo Ross of the Max Planck Institute of Radio Astronomy in Germany. New Scientist,

Using a very long base interferometry to take observations at a wavelength of 3.5 millimeters (86 GHz frequency), a team of astronomers uses computer modeling to simulate what's inside the thick cloud of plasma, dust and gas around the black hole .

blackhole wolves 35mm(S. Issaoun, M. Mościbrodzka, Radboud University / M.D. Johnson, CfA)

Top: The lower right picture shows Sgr A * as shown in the data. The top images are simulations, and the bottom left is Sgr A * with scatter removal.

She revealed that the radio broadcast of Sgr A * comes from a smaller area than previously thought.

Most of it comes from an area of ​​only 300 million degrees from the night sky in symmetrical shape. And since the black holes do not emit detectable radiation themselves, the source is probably one of two things.

"This may indicate that radio broadcasting is produced on a disc with less gas than with a radio airplane," says astrophysicist Sarah Isaun of the Radbud University in the Netherlands.

"But this will make Sgr A * an exception compared to other radio emitting black holes, and the alternative may be that the radioactive reagent points to almost us."

Active black holes are surrounded by a rotating cloud of material that falls into it as water in the sewer. As this material is absorbed by the black hole, it emits jets of particles from its rotating poles at speeds approaching the speed of light.

We are not quite sure how this happens, but astronomers believe that the material on the inside of the accretion disk is pointing at and ejected from the poles through magnetic field lines.

Since the Earth is in the galactic plane, the presence of a jet directed in our direction means that the black hole is rather oddly oriented, as if it lies on one side. (Near Centaur A galaxy, for example, there are shooting jets perpendicular to the galactic plane.)

But this orientation has been hinted before. Last year, GRAVITY Collaboration described the flames around Sgr A *, corresponding to something that revolves in our face from our perspective – like viewing the Solar System from above.

So "maybe it is true after all," said Radun Hoono Falke, astronomer at the University, "and we look at this beast from a very special point of view."

We hope the Event Horizon telescope will release the first photos of the Sgr A * event horizon – something we expect very soon – they will reveal more. And in case you've started worrying, the wavelength of 1.4 millimeters (230 GHz) will reduce light scattering by a factor of eight.

That means the long-awaited picture of the shadow of the black hole – hopefully – be amazingly detailed.

At the same time, learning data like these helps build a comprehensive picture of how these mysterious cosmic objects work.

"Understanding that black holes are working … takes more than the picture of her shadow (though incredible in her own way)," wrote Isaun on Facebook. "It takes observations of many different wavelengths (radio, X-rays, infrared, etc.) to assemble the whole story, so every piece counts!"

The team document is posted in Astrophysical Journal, and can be read entirely on arXiv.


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