#finally #image #supermassive #black #hole #center #galaxy
At the heart of our galaxy, the Milky Way, there is a “monster” – a supermassive black hole with a mass four million times that of our Sun, which sucks in all material, including gas, dust, and wandering stars. in its immense gravitational pull.
Scientists used the Event Horizon Telescope (EHT), a global network of observatories that work collectively to observe radio sources associated with black holes, to study this mysterious resident of the Milky Way. This Thursday, through multiple press conferences around the world, astronomers announced that they finally had an image of this black hole, called Sagittarius A*, or SgrA*. A long-awaited event known as “revolutionary result“, by officials of the EHT.
This result provides proof that the object is indeed a black hole and provides valuable clues about the workings of these giants, which are thought to be at the center of most galaxies, the scientists say.
In fact, this image is a long-awaited look at the massive object that sits at the center of our galaxy. Scientists had previously observed stars orbiting an invisible, compact, and very massive object at the center of the Milky Way. This strongly suggested that this object known as Sagittarius A* was a black hole, and today’s image provides the first direct visual evidence of this.
Although we can’t see the black hole itself, because it’s completely dark, the glowing gas around it reveals its signature: a dark central region (called a shadow) surrounded by a bright star-like structure. This new image shows light distorted by the black hole’s powerful gravity.
The work also revealed that the black hole rotates and is more or less oriented in front of us. “We see it from the top of the donut.“, as described by the French astronomer Eric Lagadec.
“We were surprised by how well the size of the ring matched the predictions of Einstein’s theory of general relativity.Said EHT project scientist Geoffrey Bower of the Institute for Astronomy and Astrophysics, Academia Sinica, Taipei.These unprecedented observations have dramatically improved our understanding of what is happening at the center of our galaxy and offer new insights into how these giant black holes interact with their surroundings..”
The Event Horizon Telescope collaboration was launched in 2012 with the goal of obtaining the first direct images of black holes. In 2019, the EHT team revealed the first photo of a black hole. The image, a bright ring of red, yellow and white surrounding a dark center, showed the supermassive black hole at the center of another galaxy called Messier 87 or M
A black hole is a region of spacetime with gravity so strong that nothing, not even light, can escape it. “That’s why we call it ‘black.’ Since the material that falls on it (or inside it) seems to disappear, it resembles a “hole”, the EHT scientists explain. The event horizon is the boundary surface between space and the “interior” of the black hole. This is the “region of no return”, meaning anything that crosses the event horizon can never escape.”
Since black holes do not emit light, observations are difficult. Therefore, the goal is to obtain an image of its “shadow” or “silhouette” created by the bending of light under extreme gravity. “ This is only possible with a very sharp image of the black hole in the microwave spectrum, virtually combining telescopes scattered around the Earth into a single telescope the size of our globe. The individual telescopes are placed in remote, high-altitude locations with a dry atmosphere to avoid the effect of water vapor. Your recorded signal is combined and processed to obtain the final image.“, explain the EHT researchers.
Specifically, project scientists looked for a ring of light (disturbed superheated matter and radiation flowing at tremendous speed at the edge of the event horizon) around a region of darkness that represents the actual black hole.
“The resolution of our global network of radio telescopes at this wavelength would allow us to determine the size of a ping-pong ball on the Moon.“, the researchers also specify.
ten million stars
Known as the spiral galaxy, the Milky Way viewed from above or below resembles a spinning pinwheel, with our Sun located in one of the spiral arms and Sagittarius A* located in the center. The galaxy contains at least one hundred billion stars. And its central region, towards the constellations of Sagittarius, Ophiuchus and Scorpio, has about ten million stars. But the central region is obscured from visible light as seen from Earth due to the presence of interstellar dust, which has complicated observations and analysis.
The most recent observations of stars orbiting Sgr A* give the black hole a mass of about four million solar masses. For this mass, the radius of the event horizon is about 6 million km. Your first image should allow you to better estimate its mass.
Sagittarius A* is about 26,000 light-years (the distance light travels in one year, 9.5 billion km) from Earth. The black hole M87 is therefore much more distant and massive than Sagittarius A*, estimated at 6.5 billion solar masses and located about 54 million light-years from Earth with a mass 6.5 billion times that of our Sun. Posting the photo of this black hole, the researchers said their work showed that Albert Einstein, the famous theoretical physicist, correctly predicted that the shape of the shadow would be almost a perfect circle.
“We have two completely different types of galaxies and two very different masses of black holes, but near the edge these black holes look surprisingly similar.says Sera Markoff, co-chair of the EHT Scientific Council and professor of theoretical astrophysics at the University of Amsterdam, the Netherlands.This tells us that general relativity governs these objects up close, and that any differences we see further out must be due to differences in the matter surrounding the black holes.“