In the center of the Milky Way: a successful view of the black hole

In the center of the Milky Way: a successful view of the black hole

Status: 05/12/2022 3:15 pm

Astronomers have first imaged a black hole in the center of the Milky Way. It only took many years to integrate data blocks from radio telescopes around the world.

At a press conference in Munich, held simultaneously in six other parts of the world, the European Southern Observatory, in conjunction with the “Event Horizon Telescope” project, proposed the creation of an era in astronomical research. This is the first image of a black hole in the center of our Milky Way. This is the first time that mankind has seen this mysterious object, scientifically named Sagittarius A *.

Earth, our entire solar system, and all the stars in the Milky Way orbit around this black hole. What is found at the center of this Milky Way is an amazing achievement of engineering.

Successful recording of a black hole in our galaxy

Pascal Kiss, SWR, Daily News 8:00 pm, May 12, 2022

As heavy as four million suns

The shadow of the larger object was shown. The black hole cannot be imaged because it does not emit light, but absorbs any light that comes too close to it. With its incredibly strong gravitational pull, it attracts light into its interior, but certainly attracts gas and dust and entire stars. Due to this feeding, it is now heavier than four million samples of our sun, making it the largest and heaviest object in our Milky Way.

Two problems had to be solved

The black hole was first photographed in space three years ago. It was two thousand times farther in space than the black hole now visible in the Milky Way. If so, shouldn’t the black hole in our Milky Way have been seen first rather than the farthest object in our neighborhood? But the story of the invention went the other way.

Reasons for this: The black hole that was filmed three years ago is a thousand times heavier than our “own” black hole in the Milky Way – it makes a huge difference. Director Michael Kramer says the object, which was filmed three years ago, is relatively easy to photograph while sitting very quietly in space due to its enormous mass, the Milky Way black hole being lighter, lighter, and therefore more restless. The Max Planck Institute of Radio Astronomy in Panel is involved in the “Event Horizon Telescope Project”:

To really tease the stable, solid, black hole image, we had to create new ways to work with these changes during recording.

Despite the trembling restlessness, intelligent calculation and the filtration of vast amounts of data have succeeded in creating images of “our” black hole. And researchers are not the only ones to bring tremors under control. They ignored the fact that the black hole at the center of our home galaxy was not really visible from Earth.

Image created with radio radiation

This is because the Milky Way is in the shape of a spiral with many arms and all of these spiral arms lie in the same plane. Seen from the outside, the Milky Way looks like a disk with a spiral shape. The solar system, including Earth, is part of this disk. The view from Earth to the center of this disk is often blocked by dust. That is why the film that has just been released is not a film shot in visible light, but a film created with the help of radio radiation.

Radio waves can penetrate dust and be captured by antennas. Radio waves can use signals received to create images showing what the area in space looks like from where it was first sent into space. Even if the dust waves are slightly scattered, computer programs can filter out the scattering of the image.

Requires many years of computational work

A radio telescope would not have been enough to get a sharp radio view of the center of the Milky Way. To do this, the world’s best radio telescopes must simultaneously target the center of the Milky Way. This has been going on for many years, usually once a year in the spring as part of the “Event Horizon Telescope” (EHT) program. The horizon of events is what astronomers call the edge of the black hole. That is the goal of the project – to map the large black holes in the center of the galaxy or their outer surface.

Uwe Gradwohl, SWR Science Editors, on the impression of an image of the black hole

tagesschau24 4pm, 12.5.2022

The radio telescopes used for this are spread all over the world – one of them even at the South Pole. Combining them with data lines can be very complicated and error prone. Therefore, large amounts of data are initially stored on hard drives. These hard drives are then transported to two data centers: one in Germany, the Max Planck Institute for Radio Astronomy in Panel, and the other in the United States. Only in these centers are the data of the individual radio telescopes connected and the images computed from the integrated data in the supercomputer.

The calculations took five years

In the case of the now-released film, the calculation work took a full five years. Anton Genes, director of the Max Blank Institute for Radio Astronomy in Panel and chairman of the team at the “Event Horizon Telescope” project, explains:

Editing was really hard – it took a very long time, hard work. I was so happy when I was finally able to say: We have the picture!

New research opportunities for cosmology

Through the sharpest vision of radio telescopes associated with the EHT program, the behavior of the black hole at the center of the Milky Way can be observed. It will answer questions. How much substance does it swallow? How often do radiation explosions occur? How do stars orbit very close to the black hole? Maybe even add personal images as a kind of deadline.

In this way, one can see whether Einstein’s theory of relativity describes all processes correctly, even in areas where extreme masses are gathered and extreme gravitational forces prevail. Because one thing is clear: the physics of the universe is not yet fully understood. The theory of physicists is that something is still missing in the building. What is not yet correct in existing theories can often come to light or be observed in extreme situations. What is more intense than the gravitational pull of a black hole weighing millions of suns?


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