This is the first image of the monstrous black hole that lives in the center of our galaxy.
It is known as Sagittarius A*, and has a mass four million times greater than that of our Sun.
The image shows a central dark region, where the hole resides, surrounded by light from super-hot gas that is accelerated by immense gravitational forces.
This ring is about 60 millions of kilometers, roughly the size of Mercury’s orbit around the Sun.
The supermassive monster is about 24, light years away, so it does not represent any danger to the Earth.
The image was produced by the international team of the Horizon Telescope Event Center (EHT).
In 2019, the EHT had published an image of the giant black hole at the heart of another galaxy called Messier 87 or M87.
That object is more than a thousand times large, with 6,134 millions of times the mass of our Sun.
“But this new image is special because it is our black hole supermassive“, said Professor Heino Falcke, one of the researchers of the EHT project.
“It’s in ‘our backyard’, and if you want to understand black holes and how they work, this one has the answer, because we see it in intricate detail,” Falcke, from Radboud Nijmegen University, told the BBC. )
- Einste’s predictions in confirmed and those that we continue to explore
Than is it a black hole?
- A black hole is a region of space where matter has collapsed on itself
- The gravitational pull is so strong that nothing, not even light can escape
- Black holes arise from the explosive disappearance of certain large stars
- Some are really huge and have billions of times the mass of our Sun.
- But it is clear that they energize the galaxy and influence their evolution.
It is unknown how these monsters that are found in the centers of galaxies were formed.
The trick of the EHT
Achieving this image meant a great feat.
At a distance of 26,000 light years from the Earth, Sagittarius A*, or Sgr Afor short, is a little prick in the sky. Incredible resolution is required to detect such a target.
The trick of the EHT is a technique called very long baseline array interferometry ( VLBI).
Essentially, this technique combines a network of eight widely spaced radio antennas to mimic a telescope the size of our planet.
This arrangement allows the EHT to cut an angle in the sky that is measured in arcseconds. Members of the EHT team speak of a sharpness of vision similar to being able to see a muffin on the surface of the Moon.
Furthermore, it takes atomic clocks, clever algorithms, and countless hours of supercomputing to build a picture from several petabytes (1 petabyte equals a million gigabytes) of collected data.
The way that a black hole distorts -exerting a lens effect- l In light, it means that only a “shadow” can be seen, but the glow of matter around this darkness, which spreads out in a circle known as an accretion disk, reveals where the object is.
This image looks similar to the hole in M55, but there are key differences.
- The fascinating flicker of the first black hole to be seen has image
“Because Sagittarius Ais around 1, times smaller, its structure ring changes on time scales that are 1,10 times faster,” explained team member Dr. Ziri Younsi, from University College London, in the United Kingdom.
“It’s very dynamic. The ‘hot spots’ you see in the ring move day by day”.
The superheated excited gas, or plasma, in the ring travels around the black hole at a significant fraction of the speed of the light (300 000 km/s).
The brightest regions are probably places where material is moving towards us and where its light emission is being energized.
These rapid changes in the neighborhood of Sgr Aare part of the reason why it has taken much longer to produce an image compared to M87.
There is not doubts
The interpretation of the data has been a more difficult challenge.
The telescope observations for both black holes were actually acquired during the same period, in early 2017, but M87, at its largest size and distance from 15 millions of light years, appears static compared to Sgr A*.
Scientists have already started implementing the measurements in the new image to test the physics we currently use to describe black holes.
So far, what you see is fully consistent with the equations established by Einstein in his theory of gravity, general relativity.
For decades it was suspected that a supermassive black hole lives in the center of the galaxy. lax.
What else could produce gravitational forces that accelerate nearby stars through space to speeds of up to 26,000 km/s (for comparison, our Sun is gliding around the galaxy at a speed of only 230 km/s )?
Interestingly, when the Nobel Prize committee honored astronomers Reinhard Genzel and Andrea Ghez with their physics prize in 2019 for his work on Sgr A*, the citation only spoke of “a supermassive compact object”.
It was a margin of maneuver in case and some other exotic phenomenon will turn out to be the explanation.
But now there are no doubts.
In August, the new super space telescope, James Webb, will put your gaze on Sgr A*.
You won’t have the resolution to get a direct image of the black hole and its accretion ring, but with your Incredibly sensitive infrared instruments will allow the study of the environment of the black hole.
Astronomers will study in unprecedented detail the behavior and physics of hundreds of stars revolving around the black hole.
They will even look to see if there are any star-sized black holes in the region, and for evidence of concentrated clumps of invisible matter or dark.
“Every time we have a new tool that can take a sharper picture of the universe, we do everything possible to train her in the galactic center, and inevitably we learn something fantastic,” said Jessica Lu, a professor at the University of California Berkeley, USA, who will lead Webb’s campaign.
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