The first image of a black hole in the same galaxy as Earth is taken



The figure of the giant black hole ' Sagittarius A * ' located in the center of the galaxy 'Milky Way Galaxy' including the earth was photographed. This is the second black hole shot following the

2019 M87 supermassive black hole (M87 *) shot .

Succeeded in shooting a black hole in the center of the Milky Way Galaxy for the first time | EHT-Japan
https://www.miz.nao.ac.jp/eht-j/c/pr/pr20220512

First successful shooting of a black hole in the center of the Milky Way Galaxy | National Astronomical Observatory of Japan (NAOJ)
https://www.nao.ac.jp/news/science/2022/20220512-eht.html

First image of the supermassive black hole at the center of our own Milky Way galaxy --Black Hole Cam
https://blackholecam.org/first-image-of-the-supermassive-black-hole-at-the-centre-of-our-own-milky-way-galaxy/

Black holes have such a strong gravity that even light cannot escape, so they cannot be captured by ordinary astronomical telescopes. Therefore, the project ' Event Horizon Telescope (EHT) ' was launched to build a global virtual telescope by linking radio telescopes installed all over the world to photograph black holes.



EHT observed a black hole in April 2017, processed several petabytes of shooting data, and released an image of M87 * at the core of the

Virgo cluster in 2019.

'Event Horizon Telescope' aiming to capture black hole shadows will hold a press conference --GIGAZINE



Even after the image of 'M87 *' was released, the EHT project team continued to analyze the shooting data and worked on the visualization of 'Sagittarius A *' in the Milky Way galaxy. The following movie shows the difference in size between 'Sagittarius A *' and 'M87 *'.

Size comparison of the two EHT black holes --YouTube


'Sagittarius A *' is about 27,000 light-years away from Earth, and 'M87 *' is 55 million light-years away from Earth. For this reason, 'Sagittarius A *' and 'M87 *' appear to be about the same size from the earth ...



If both black holes are placed at the same distance from the earth, the 'M87 *' will be large enough to extend the screen. In other words, the 'Sagittarius A *' that was the subject of this observation is much smaller than the 'M87 *' that was visualized in 2019.



Around 'Sagittarius A *' and 'M87 *', gas orbits at a speed close to the speed of light. The gas that orbits 'M87 *' requires several days or weeks per lap, but in the case of 'Sagittarius A *', the gas orbits once in a few minutes, so during observation by EHT. The brightness and pattern of the gas that orbits 'Sagittarius A *' changes rapidly. For this reason, it was much more difficult to derive one image compared to 'M87 *'.

The research team used a method of 'taking the average of the images obtained from the observation data' in order to derive the image of 'Sagittarius A *'.

First, we integrated a huge amount of observation data into four clusters ...



One image was derived by averaging the four clusters. In the image, 'Sagittarius A *' is reflected in a donut shape.



Below is an array of images of 'Sagittarius A *' and 'M87 *'. Sera Markov, one of the chairs of the EHT Scientific Advisory Group, said, 'It's a separate black hole with completely different masses in two very different galaxies, but if you look only in the immediate vicinity of these black holes. 'It looks surprisingly similar.' 'This is because the general relativity dominates the immediate vicinity of the black hole, and the difference seen when far away from it is the difference in the material around the black hole. It means that it is. '



In addition, Keiichi Asada, an EHT researcher who belongs to the Astronomical and Astronomical Physics Institute of the Taiwan Central Research Institute, said, 'We got images of two black holes, one of which is a huge black hole that exists in this universe. It is one of the largest and the smallest of all, so it is possible to examine how gravity behaves in such extreme environments in more ways. ', He talks about the significance of the achievements of ETH.

in Science,   Video, Posted by log1o_hf