Moreover, we can also start to investigate the physics of the material surrounding the black holes. It is therefore extremely satisfactory to do these observations so that we really know it exists. We have never had any direct imaging of black holes. By calculating the speed of the stars, we would conclude that the mass of the central object must be so high that it has to be a black hole. We observed orbits of stars around black holes. (Until these images were taken), all the proof we had about the existence of black holes was indirect. Why is it important to capture images of black holes? Three years ago, the EHT Collaboration captured the first image of a black hole. These two instruments are extremely sensitive. The other instrument, called NOEMA or Northern Extended Millimeter Array, is an array of 12 antennas, each of which is 15 metre in diameter. One is an antenna of 30 metre diameter located in Sierra Nevada in Spain. What are the features of these two telescopes? Out of the ten telescopes that form the EHT array, two belong to IRAM. ![]() That’s why we cannot observe the vicinity of the black hole in the optical wavelength. There is a lot of gas and dust in the interstellar medium, which absorbs light at optical wavelength. We needed to observe at radio wavelengths for one simple reason. The (observational) data was combined by using a very complicated mathematical process to create this image which is not an optical image. We needed to have atomic clocks at all these sites to make sure the synchronisation was perfect. All the observations from different sites were carried out simultaneously. We have 10 observatories all over the planet. To observe the black hole, we used a network of radio telescopes that operate in the millimetre (wavelength) domain. We knew there was a black hole (at the centre of our galaxy) but we never had direct imaging of it.Īll the proof we had of its existence was indirect. How did you capture the image of Sagittarius A*? It is located at 27,000 light years away. The Sagittarius A* is four million times more massive than the Sun, which is already an incredibly massive object. ![]() There is a black hole at the centre of every galaxy, not just the Milky Way. However, there is a trick to observing it. The first-ever image of a black hole was released Wednesday by a consortium of researchers, showing the 'black hole at the center of galaxy M87, outlined by emission from hot gas swirling. We cannot observe a black hole because nothing can get out of it. It is so massive that nothing, not even light, can escape from it. What is a black hole and why is it located at the centre of our galaxy?Ī black hole is one of those fascinating objects whose presence was predicted by Albert Einstein. ![]() In an interview with RFI’s Dhananjay Khadilkar, Gueth talked about the monumental effort involved in capturing this image, and its significance. This was the result of observations conducted using a global array of radio telescopes that form the EHT.ĭr Frederic Gueth, deputy director of the Grenoble-based Institut de Radioastronomie Millimetrique (IRAM), is one of the scientists involved in the project.
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