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Our first picture of a black hole was a highlight for science. But we can not stop there. We need better images that provide more information. It is so that we will learn more about these strange giants who break the rules.
A group of astronomers from the Radboud University of Nijmegen, the Netherlands, in collaboration with the European Space Agency and other partners, is currently developing a plan to obtain much more accurate pictures of black holes.
The first image of a black hole by the Horizon Telescope Event (EHT) is a scientific triumph and a feat of cooperation, engineering and technology. Add to this the innate curiosity of our species for nature. It's a powerful and effective blend.
But the picture was rather blurry, is not it? It's always a triumph, and a lot of research and new articles will result. But could it be even better?
The group of scientists planned to launch radio telescopes in the space to get clearer pictures of black holes. They published an article in the journal Astronomy and Astrophysics detailing their plans. Their ultimate goal? To test again the theory of general relativity of Einstein.
EHT is a group of radio telescopes from around the world working together. They work on the principle of interferometry.
Together, the scopes act as a kind of virtual telescope the size of the Earth. That's how well we had a telescope big enough to see a black hole. But the EHT is bothered by the same thing as other terrestrial telescopes: the Earth 's atmosphere.
The Earth's atmosphere can create a lot of problems for astronomers. Telescopes must somehow adapt to the atmosphere to collect images of objects at great distances. This is why telescopes are built in special places: ideally in arid environments at high altitude.
EHT radio telescopes are located at high altitudes around the world. They are in the Alps, Sierra Nevada, Atacama and Hawaii. But they are still limited by the earth's atmosphere. And this atmosphere prevents the radio waves the highest frequencies to achieve the objectives.
Another factor limiting the effectiveness of the ISE is the size of the Earth. On Earth, we can only use interferometry to connect fields of application as far apart as the "breadth" of the Earth. Thus, any virtual telescope is limited by the size of our planet itself.
The authors of the article have a solution to both the problem of the atmosphere and the problem of the size of the Earth. Put the radio telescopes in place.
They call their proposed project Event Horizon Imager (EHI) and say that it can produce black hole images five times sharper than the EHT.
The idea is to put into orbit two or three satellites that would serve as radio observatories. There, they would be released from the two limitations of the ISE.
"There are many advantages to using satellites rather than permanent radio telescopes on Earth, such as with the Horizon Event Telescope (EHT)," says Freek Roelofs, Ph.D. candidate at Radboud University and lead author of the Ph.D. ; article.
"In space, you can make observations at higher radio frequencies because the frequencies of the Earth are filtered by the atmosphere.The distances between the telescopes in the space are also larger This allows us to take a big step forward, we could take images with a resolution more than five times what is possible with ISE. "
The team created simulated images of black holes that represent what the IED could see.
The EHI could capture images with a resolution five times higher than the EHT. (F. Roelofs and M. Moscibrodzka, Radboud University)
Sharper images of a black hole will lead to better information that could be used to further test Einstein's theory of general relativity.
"The fact that satellites move around the Earth has considerable advantages," says radio astronomy professor Heino Falcke. "With them you can take almost perfect pictures to see the real details of the black holes.If small deviations from the Einstein theory occur, we should be able to see them."
Other tests of Einstein's theory of general relativity are one of the main goals of the EIH. In an email exchange with Univers
Today, the main author, Freek Roelofs, explained it as follows: "Einstein's theory of general relativity predicts exactly the size and shape that a black hole shadow should have .The alternative theories of gravity predict different sizes and shapes, but the difference with the prediction from general relativity is In general, to be able to distinguish between general relativity and other theories of gravity, we need 39 high-resolution images that we can only obtain from spatial observations. "
Yes, there are other theories of gravity. Although every time scientists are able to test Einstein's TGR, the evidence corroborates this theory, but some issues remain to be resolved.
There are many alternative theories about gravity in the scientific world, and they are mostly related to our unanswered questions about black holes, dark matter and black energy.
There are dozens of alternative theories about gravity, and most of them have not withstood the evidence well. But they exist because if one of those experiments designed to test Einstein's TGR proves that it's wrong, we have to work with another theory.
There are many challenges to face if the IHE materializes someday. With the EHT, each observatory records its data on a hard drive that is delivered to a data center.
All data from each oscilloscope is combined using an atomic clock for extreme accuracy. But how will it work in the space?
"With the EHT, hard drives containing data are flown to the treatment center.This is obviously not possible in the space," said Volodymyr Kudriashov, researcher at Radboud Radio Lab, also at ESA / ESTEC. According to the paper, a laser link could be used to send the data to Earth for processing.
They already have a precedent, and future space missions will further refine laser communications.
Another challenge is the precise position and speed of the satellites needed to produce sharp images.
"The concept requires that you be able to know precisely the position and speed of satellites," said Kudriashov. "But we really believe that the project is achievable."
The EHI would work in conjunction with the EHT as a kind of hybrid interferometer, combining data from all Earth observatories with data from orbital observatories. The best of both worlds.
"Using a hybrid system like this could offer the ability to create animated images of a black hole, and you may be able to observe even more weaker sources," Falcke said.
This article was originally published by Universe Today. Read the original article.
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