First image of Sagittarius A* revealed, the supermassive black hole at the center of the Milky Way – Observer

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It was The first image of the supermassive black hole at the center of the Milky Way, Sagittarius A*, has been revealed.. It is also the second image in the history of a black hole, after the image taken in the Messier 87 galaxy. The image revealed on Thursday is the first concrete evidence that a supermassive celestial body at the center of the galaxy where Earth is actually a supermassive black hole. And it took a lot of data to get it, if it were printed on A4 sheets, the stack of papers would reach the moon.

What you see in the picture is not the black hole itself: these celestial bodies have such a gravitational force that nothing, even light, can escape from them. What reveals the black hole’s silhouette is the glowing gas being swallowed up by this central region., which is called the shadow – it is inside it the point where all the laws of physics are broken, the singularity. “The new view captures light that is curved by the strong gravitational pull of the black hole, which is four million times larger than our sun,” explains the press release from the European Southern Observatory responsible for the discovery.

Although it is gigantic, for being so far away, Sagittarius A* black hole is almost impossible to detect from Earth using the visible light spectrum. Scientists compare it to looking at the moon and searching for a doughnut. So astronomers from the Event Horizon Telescope (EHT) project have been examining the infrared spectrum and taking pictures every night since 2017.

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Scientists from the Event Horizon Telescope (EHT), a network-connected radio telescope project that monitors the planet’s two closest black holes, scheduled a press conference Thursday at 2 p.m. in Lisbon. Announces “Revolutionary Results About the Milky Way”. It was not known what would be announced: only that it is associated with Sagittarius A*, a radio source in the center of the galaxy believed to be a supermassive black hole.

Expectations were already high because This is the same team that revealed in April 2019 the first image of a black holewhich is located in the elliptical galaxy Messier 87. And also because of what is being interpreted as a clue about what was coming in an article by the European Southern Observatory involved in this project, published last week: “As you can see, we have already come to a point where we literally write a card Sgr identity A*; and no ID is complete without an image. Can the Event Horizon Telescope collaboration provide one?”

He continues: “The EHT is so powerful that it was able to take the first-ever image of a black hole – the supermassive image found at the center of galaxy M87, more than 50 million light-years away. This image was released in 2019 and The following results of EHT are widely expected“.

The first image of a black hole. How do you visualize something unseen and what does it show in the great “puzzle of physics”?

Sagittarius A*, the name scientists shortened to Sgr A*, is a black hole with it It has a mass four million times the mass of the Sun. It’s 27,000 light-years away from Earth – that is, it would take 27,000 years to get there if it traveled at the speed of light, which is 300 million meters per second – and is also the closest to the planet.

But it’s not his first image of a black hole: between Earth and Sgr A* there are more objects that get in the way of observations, as you look at the Milky Way. To observe the Messier 87 galaxy, scientists look outside the Milky Way, in a direction where the view is clearest. In fact, the image does not show the black hole itself (which is not visible), but The light it swallows as it crosses the event horizon The limit that the force of gravity exceeds so that nothing can escape from it.

This is the first image of a black hole. Einstein was right again

The first indications of the existence of the Sgr A* date back to the 1930s, when engineer Karl Jansky was trying to rotate an antenna he had made using four Ford Model-T tires. The goal was to find potential sources of interference in radio transmission. Karl Jansky, unsurprisingly, realized that much of this interference came from weather events such as storms. But He also detected a slight, continuous distortion coming from the constellation Sagittarius. In this region of the night sky, the center of the Milky Way appears to be on Earth.

Twenty years later, astronomers He began to discover more and more very bright radio sources across the universe, which is also located in the middle of neighboring galaxies. He called them “quasars” – “quasi-stars” – because they looked like stars in very dim light. It wasn’t until 1963’s Martin Schmidt novels showed that, after all, quasars should radiate intensely when observed in the (invisible) radio wave spectrum. One of them, 3C 273, should emit 1,000 times more energy than the entire Milky Way galaxy.

Scientists have begun searching for answers to the mystery of quasars. First came the theory: the energy they observed and discovered on Earth It was a glowing substance being sucked into a black hole. Then came the practice: looking for evidence to support this hypothesis in the center of the Milky Way, where the closest quasar to Earth was. But there was a problem: if the difficulty of studying extragalactic quasars was the enormous distance that separates us from them, which did not allow us to distinguish stars and gas clouds, then the problem here was the interstellar clouds of gases and dust that absorb visible light. Coming from the center of the Milky Way.

For this reason, in the seventies, observations began to be made in the infrared spectrum. Charles Townes studied the motions of gas around Sgr A* and found that the mass of the quasar, at least in its vicinity, should be between two million and four million times the mass of the Sun – properties consistent with those of a black hole. But this was not enough: after all, the motion of the gas can be explained by factors other than gravity, such as magnetic fields. and the Technology has not allowed it to get any closer to the center of the mysterious Milky Way – a few light years away, which may affect the calculations.

During the 1990s, in addition to observations of gas clouds in the center of the Milky Way, scientists began to look at the stars. They even found stars in a month of light from Sgr A* that It revolves around this celestial body at a speed of 2000 kilometers per second. This was the most obvious evidence that the Sgr A* quasar was an object with an extremely compact mass and an amazing gravitational force. After discovering a star 17 light-hours away from Sgr A* (four times the distance between the Sun and Neptune), scientists concluded that it was indeed a supermassive black hole. That was in 2002. Since then, scientists have been analyzing the nearest and closest celestial bodies to get more information. and a picture.

The image of the black hole in the center of the Milky Way and the image captured in the galaxy M87 look very similar, but the two celestial bodies are very different: after all, Sgr A* is a thousand times smaller and less massive than M87*. “We have two very different types of astrophysical holes and two completely different masses of black holes, but they are remarkably similar near the black hole boundary,” said Cera Markov, chair of the EHT Science Council.

This is important because such information has implications for the interpretation of Einstein’s general theory of relativity. The mystery surrounding black holes is that physicists cannot describe the laws of physics that prevail within them – they are points in the fabric of space-time (the fabric of which the universe is made up, consisting of three spatial dimensions and the line of space). time) cUnder these extreme conditions, all known laws of physics are broken. But this evidence means that Einstein’s theory “rules even near these objects” and that “any differences we see from afar must be due to differences in the material surrounding black holes.”

it took An enormous network of radio telescopes for imaging Sgra A*consisting of Arizona Radio Observatory (USA), Atacama Pathfinder Experiment (Chile), IRAM 30m Telescope (Spain), James Clerk Maxwell Telescope (Hawaii), Millimeter Large Telescope (Mexico), Sub-Scale Array (Hawaii), Array Atacama Large Millimeter (Chile) and Antarctic Telescope.

They are all called the Event Horizon Telescope, and it is a project funded by the European Union through the Research Council in Europe. It uses a technique called “long fundamental interferometry”, where u . is usedThe m radio signal of astronomical origin is captured by various telescopes. When several radio telescopes scattered around the Earth are programmed to work together, they become a single observatory the size of our planet.

What this army is doing is bypassing the black hole. Literally. Since direct appearance is worthless, because the area itself is completely invisible, The eight telescopes look at its surroundings first. Matter, when sucked into a black hole, can get extremely hot temperatures due to friction. Gas forms a hot disk around the black hole and falls, causing the black hole to grow. It is the light of this luminous gas captured by the Event Horizon Telescope.

It sounds simple, but it takes more work when that information hits the ground running. It’s just that not all telescopes get the same information at the same time, so the telescopes in the Atacama Desert Saw might escape the telescope’s view of Antarctica. This gives the scientists behind the Event Horizon Telescope an additional mission: Development of an algorithm that collects the information detected in each of the telescopes and fills the gaps of data that was not captured by any of them. Only with all these steps completed can a true picture of the silhouette of a black hole be obtained. Which we saw this Thursday.

The latest big news from the European Southern Observatory was announced in April 2020, when observations made with the Very Large Telescope, in Chile, showed that a star is orbiting the supermassive black hole at the center of the Milky Way.And changes as predicted by Albert Einstein’s general theory of relativity.

S2, a star in the dense stellar cluster around Sgr A*, has a rosette-shaped orbit — not an ellipse, as Isaac Newton’s theory deduces. Observations show that the star is approaching the black hole by a distance of up to 20 billion kilometers – 20 times greater than that separating the Earth from the Sun – and It enters at about 3% of the speed of light. It orbits the black hole every 16 years, but instead of making an orbit like that traditionally found on a planet around a star, it makes many ovals in different planes around the black hole.

S2 orbit advances, which means that the location of the closest point to the supermassive black hole changes with each orbit, so that the next orbit is rotated relative to the previous one, causing its path to follow the shape of the rose. General relativity gives us an accurate prediction of how much the orbit will change and the latest measurements perfectly match the theory,” the observatory announced two years ago.

The next step in this investigation will be the Very Large Telescope (ELT), which is the largest telescope at the European Southern Observatory. with him”Maybe we can catch stars near the black hole to feel spinning and spinning of this supermassive object,” explained one of the project scientists, Andreas Eckart. This would be important because it would allow the measurement of yarn (factor related to the rotation of the celestial body) and to more precisely determine the mass of the black hole at the center of the Milky Way.

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