Astronomers have released for the first time an image of a supermassive black hole in the center of our Milky Way galaxy. This result provides overwhelming evidence that the object is indeed a black hole and provides valuable clues about the operation of such giants, which are believed to be located at the center of most galaxies. The image was produced by a global research team called the event horizon telescope (EHT) collaboration using observations from the global radio telescope network. Theoretical physicists at Goethe University in Frankfurt have played a role in interpreting the data.
The image is an observation of a huge object in the center of the Milky Way galaxy. Scientists have previously seen stars orbiting an invisible, compact, very large object in the center of the Milky way, which strongly suggests that the object called Sagittarius A * is a black hole, and this new image provides the first direct visual evidence.
Although we cannot see the black hole itself because it is completely dark, the glowing gas around it shows an obvious feature. A dark central area (called "shadow") is surrounded by a bright ring structure. Astronomers have captured light bent by the strong gravity of a black hole four million times the mass of our sun.
The black hole is about 27000 light-years away from the earth. In order to image it, the research team created a powerful eht, which connects eight existing radio observation stations on the whole earth to form a single "earth size" virtual telescope. Eht observed Sgr A * for many nights and collected data for many hours, which is similar to using long exposure time on the camera.
Astronomers must theoretically interpret the large amount of observation data collected. To this end, a research team led by Luciano rezzolla, a theoretical astrophysicist at Goethe University in Frankfurt, used a supercomputer to simulate the appearance of a black hole observed by eht based on the observed Sgr A data. In this way, scientists created a database containing millions of images. Then, they compared the image library with thousands of different images of EHT to infer the properties of Sgr A .
The breakthrough came after the EHT cooperation released its first image of a black hole, known as M87 *, at the center of the more distant Messier 87 Galaxy in 2019.