Just over a month ago, an international team of astrophysicists of the project Event Horizon Telescope (EHT), in which scientists combined several radio telescopes in different parts of the world to create a huge virtual radio interferometer the size of the Earth, published the first ever photo of a black hole. Now another group of scientists, including astronomers from the Dutch University of Nijmegen and specialists of the European space Agency (ESA) has set a goal to get even clearer images of the black hole, which would allow to verify the General theory of relativity. Researchers have proposed the concept that, in their opinion, will allow to solve this problem. Their idea is accepted for publication in the journal Astronomy & Astrophysics.
The concept of European scientists, called the Event Horizon Imager (EHI), involves placing a circular orbit around the Earth two or three satellites. The researchers conducted computer simulations that show how much more detail you can get shots of the black hole Sagittarius A, which is located in the center of our galaxy, and became the purpose of the ground of the virtual telescope EHT.
Five times clearer images
“There are many benefits of using stationary satellites instead of radio telescopes on Earth, such as the same Event Horizon Telescope (EHT),” says freek Roelofs, PhD candidate of the University of Nijmegen and lead author of the new article.
“In space you can make observations at higher radio frequencies, because on the Earth they are filtered by the planet’s atmosphere. In addition, the distance between the telescopes in space can be even more. This will allow us to make a big step forward. We can get images that are quality will be five times higher than the quality of the images that can be obtained through EHT” — adds the scientist.
The ability to obtain clearer images of the black hole will allow you to collect more information which will be useful for a more accurate test of the General theory of relativity.
“The fact that the satellites will move in an orbit around the Earth also provide us with additional benefits”, says Professor Heino falcke radio astronomy.
“Because of this you will be able to get a almost perfect image and consider the real parts of a black hole. If in reality there are some inconsistencies of Einstein’s theory, we will be able to see them.”
According to the researchers, EHI will be able to image five additional black holes that are smaller than those, which explores the virtual ground telescope EHT. Speech in the latter case is a Central black hole of our galaxy, Sagittarius a, and the Central black hole of M87 is a massive elliptical galaxy Messier 87, located in the constellation Virgo.
In space permission EHI will be five times higher than terrestrial virtual telescope EHT. The picture of black holes can be obtained with an even higher level of detail. The image in the upper left corner shows the black hole Sagittarius A, which saw EHT at a frequency of 230 GHz. Top right shows a computer model. In the lower left corner shows a model of Sagittarius And with observations at a frequency of 690 GHz. Bottom right image shows the computer model, what it can see outer virtual telescope EHI
The researchers simulated image that would be obtained when using different visualization technologies. For this they turned to the previously developed models of the behavior of the plasma and radiation around the black hole.
“From a scientific point of view, the models look very promising, but will have to overcome several technological challenges to achieve such a result in reality,” says Roelofs.
To assess the technical feasibility of the project on creation of space of the virtual telescope EHI astronomers have joined forces with experts of the European space research and technology (ESTEK), created by ESA.
“This concept requires a very precise calculation of the position and velocities of the satellites. But we believe that the project is really feasible,” — says Vladimir Kudryashov from the laboratory of the University of Nijmegen, which also cooperates with the ESTEK.
Experts note that it is also important to consider how scientists will be able to collect satellites data.
“Data from ground-based virtual telescope EHT was recorded on the hard disk, and then through the aircraft was transported to the center of deciphering. This approach, of course, inapplicable to the cosmos,” says Kudryashov.
Scientists propose to transmit the data to use lasers. In this part the data collected will be processed directly on Board the satellites themselves, and then be transmitted to Earth for further analysis.
“Such technology in the space already used,” — added Kudryashov.
The hybrid system
At its core, the idea of specialists from ESA and the University of Nijmegen is designed to work independently of the virtual space telescope EHI. However, scientists are considering the use of hybrid and unique system, which will be combined into a single network power the virtual ground and orbital telescope EHT EHI.
“The use of such hybrid system can provide us the ability to create a dynamic image of a black hole, and to consider even more weak sources of radio emission in the surrounding region of the object,” says falcke.