The Galaxy M87, also known as Virgo A or NGC H487 is a supergiant elliptical galaxy. It is one of the brightest radio sources among the thousands of galactic systems in the sky. It is also a powerful X-ray source which suggests the presence of very hot gas in the galaxy.
By general theory of relativity Albert Einstein proposed the existence of black holes. It has been known for decades. To prove the presence of black hole, the stars are being rotated around the invisible object in the centre of the Milky Way Galaxy.
Evidence of The Black Hole
The first ever direct visual evidence of a black hole in the centre of the galaxy M87 was released on April 10, 2019.it is located 55 million light years from earth. A team of more than 200 astrophysicists worked hard together to capture the image but the black hole image was not shown because it was black so it was invisible against the backdrop of the space. The scientists used radio signals to capture the black hole’s shadow.
Due to the gravitational force from the black hole, the light bends around the hole as a boundary and hence a bright ring is formed around the boundary of the black hole. The Event Horizontal Telescope project director Sheperd Doeleman told the reporters at the press conference in Washington DC that the evidence for a black hole is known now.
With Einstein’s prediction the evidence and the shape of the shadow is consistent. The black hole spins fast enough and they form a wormhole in spacetime. The M87 black hole is about 6.5 billion times the mass of the sun captured using the Event Horizon Telescope.
Operation Behind The First Ever Image of Black Hole
Combining a network of eight powerful ground based telescope a radio array was formed as wide as the earth. The observatories, located in Hawaii, Arizona, Chile, Mexico, Spain and Antarctica. The black hole’s radio were capture individually over four nights in April 2017 when the weather was optimal in all the six regions. Each telescope acquired the data from the target black hole.
Physical hard drives were used to store the data. It is then transported to the central location. It was stitched together by a super computer to form the image of the black hole’s shadow. Due to its enormous mass and relative time to earth, the researches who targeted the M87’s black hole say that the image produced is slightly blurry.
They say that the future image will be more clear because more telescopes are added to the Event Horizon Telescope. Sheperd Doeleman said that the collaboration is still working on producing an image of the Milky Way’s black hole and hoping to get that very soon. The team also believes that they will be able to fine-tune the photo further.
The Event Horizon Telescope has also been trying to image the black hole closer. They had two primary targets. First was the Sagittarius A* which occupies 25,000 light year away from the earth at the centre of the Milky Way galaxy. It has a mass of about 4m suns. It is small enough that appears about the same size in the sky as much further M87. The second target was a supermassive black hole in the galaxy M87 into which the light and matter has disappeared.
The data collected by the telescope are currently in process by the scientists. The black holes are regions in space where the pulling strength of gravity is so powerful that even lights is unable to escape. Size and mass of the black hole can vary widely. The intense gravity is caused by the matter that is compressed into a small space. The black hole light is brightest among all the stars in the galaxy due to the far distance from the earth. Researches believe that the massive black holes which exist in the centre of the every galaxy in the universe were formed at the same time as their galaxy.
As the result the structure of black hole is nearly circular, as per the prediction of Einstein. It states that the observed image is consistent with expectations for the shadow of the spinning Kerr black hole as predicted by general relativity.