Astronomers find black hole that was born giant – 12/03/2023 – Messenger Sideral

One of the most mysterious categories of cosmic objects is supermassive black holes. Practically every galaxy has one of them in its central region, and we know that they have ancient origins. What astronomers don’t know is how exactly they form. Now a study seems to point to an answer to at least some of them.

The work of Akos Bogdan, from the Harvard & Smithsonian Center for Astrophysics, benefited from observations from the James Webb Space Telescope (which takes images in infrared) and the Chandra X-ray Observatory. The first made it possible to identify a very distant galaxy, UHZ1, whose Light that now reaches us came from there 13.3 billion years ago – just some 500 million years after the Big Bang. The second captured the X-rays emitted from the surroundings of the central black hole, from the disk of spiraling gas that surrounds the object.

Detection was only possible thanks to extra help from nature. Between this galaxy and Earth, a large cluster of galaxies known as Abell 2744 stands between. The immense presence of matter there produces enough gravity to bend the rays of light coming from the background object, acting like a lens, magnifying them. Thus, even very far away, this galaxy entered the range of telescopes.

By analyzing the data, the group led by Bogdan estimates that the supermassive black hole in the galaxy UHZ1 has 10 million to 100 million solar masses. So far, nothing too shocking. The surprise comes when this number is compared to the combined mass of the stars in the entire galaxy – more or less the same.

It’s a stark contrast to what we typically see in nearby galaxies, where the mass of the supermassive black hole, although sometimes much greater than that, accounts for a minimal percentage of the galactic stellar mass, something like a thousandth.

The fact that the mass of stars in UHZ1 is so small, compared to the supermassive black hole, indicates that there would not have been time for it to have grown to this size via the conventional route, in which stellar black holes (the result of the collapse of massive stars) of 10 to 100 solar masses collide with each other until a colossal object is produced.

Instead, scientists are convinced that this supermassive black hole was born giant, from the direct collapse of a gas cloud, with a mass equivalent to that of some 10,000 to 100,000 suns. “The combination of this high mass of the black hole and a large ratio of the mass of the black hole to the galaxy just some 500 million years after the Big Bang was theoretically predicted and is consistent with a picture in which black holes would originate in heavy seeds”, write the researchers, in an article published in Nature Astronomy. They believe this is the first confirmed detection of a black hole that formed by direct collapse of a gas cloud.

Now, would this be the rule or the exception? Only the future will tell that, as telescopes like Webb and Chandra dive deeper into the Universe in search of landscapes from its beginnings.

This column is published on Mondays in print, in Folha Corrida.

Follow Sidereal Messenger on Facebook, TwitterInstagram and YouTube

LINK PRESENT: Did you like this text? Subscribers can access five free accesses from any link per day. Just click the blue F below.