This confusing scenario, which further analyzes will have to confirm, occurred between 500 and 700 million years only after the Big Bang that occurred 13.8 billion years ago. Either in the very young Universe, therefore very distant.
These are just a few small glowing dots…one of the scientists involved in the research, assistant professor Erica Nelson, from the University of Colorado, nicknames them UFOs – the acronym used by English speakers for our UFO – by diverting the original meaning: “Ultra-red Flattened Objects”, or “ultra-red flattened objects”, because these distant galaxies look like flying saucers. And these spots are stirring astronomers.
The James Webb Space Telescope (JWST), operational since July 2022, was able to explore this unknown and distant region of the Universe thanks to its instrument NIRCam and its powerful vision in the infrared, a wavelength invisible to the human eye and whose observation allows us to go far back in time.
He unearthed these six galaxies, much more massive than expected in this primordial Universe, reports a study published in Nature. Two of them had already been pointed by the Hubble telescope, but had gone unnoticed as the light emitted was weak.
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According to the interpretation of the new JWST images, these six galaxies – called “candidates” at this stage because the discovery will have to be confirmed by spectroscopic measurements – contain many more stars than expected. One of them would contain up to 100 billion: “I almost spat out my coffee”, writes Ivo Labbe, first author of this research.
The impossible discovered
Of the six massive candidate galaxies, seen 540 to 770 million years after the Big Bang, this one could contain as many stars as our current Milky Way, but be 30 times more compact. [I. Labbe (Swinburne University of Technology)/NASA, ESA, CSA – Handout via Archyde.com]
“We discovered the impossible. Impossible early, impossibly massive galaxies. It’s about the size of the Milky Way, which is crazy,” he enthuses.
It took our galaxy 13.8 billion years to form this quantity of stars, when this young galaxy would have done as much in just 700 million years “that is twenty times faster”, develops this researcher from the Swinburne University of Technology in Australia: “The Universe was only 5% of its current age”.
Such distant galaxies of this size have no place in the current cosmological model which tries to understand the structuring of the Universe: “The theory tells us that at these remote ages, the galaxies are very small and grow very slowly. You would typically expect them to be 10 to 100 times smaller in terms of the amount of stars,” he said.
“The Pattern Cracks”
Finding such big ones, “it’s like jumping off a cliff” in his eyes.
What would go wrong? The suspect could well be dark matter, the mysterious invisible matter that populates the Universe. While scientists can’t detect it, they know its behavior quite well and know that it plays a key role in galaxy formation.
“Dark matter must ‘fit together’ to form a halo which attracts towards it the gas from which the stars will be born”, deciphers Ivo Labbe. However, this “coagulation” process is supposed to take a long time. (read card).
It would therefore seem that “things have particularly accelerated” in this primordial Universe, which would have been “more efficient than we thought” in making stars, comments David Elbaz, astrophysicist at the Atomic Energy Commission (CEA) , who did not take part in the study.
This could be explained by the process of expansion of the Universe which is accelerating faster than we thought, notes this scientist involved in the telescope observation program developed by NASA.
The subject agitates the debate among cosmologists and this discovery is “all the more exciting as it is one more indication that the model is cracking”, analyzes David Elbaz.
The European Space Telescope Euclidwhich is to be launched into orbit this summer in an attempt to unlock the secrets of dark matter, should help clear up the mystery, he points out.
Professor Labbe cites the black swan theoryaccording to which an unpredictable and improbable event, if it occurs, has a considerable impact: “If only one of the six candidate galaxies is verified, the theory will have to be reviewed”.
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Stéphanie Jaquet and the ats