NOIRLab
Three newly discovered ultra-faint dwarf galaxies tell the story of the Universe, but they have not formed new stars for millions of years.
An international team of scientists has discovered 3 ultra-faint dwarf galaxies that contain just hundreds or thousands of stars.
As highlighted by , this number is “insignificant” when compared to other galaxies, which usually have hundreds of billions of stars. This is why these are called “ultra-weak”.
Published in December in The Astrophysical Journal Letters, emphasizes that these galaxies, called Sculptor galaxies, were found in a isolated regionaway from the gravitational influence of larger structures.
But why don’t they form stars?
Researchers believe that some events that took place at the beginning of the Universemay have caused the “infertility” of these galaxies, turning them into true “ghost cities”.
One possible example is the Epoch of Reionizationduring which intense ultraviolet radiation heated and dispersed the gas in several newly formed galaxies. ”
“We don’t know how powerful or uniform this Reionization effect was, but it may be that the Reionization was irregular and did not occur everywhere at the same time,” explains researcher David J. Sand.
“We found three galaxies of this type, but it is not enough. It would be great if we had hundreds of them. If we knew what fraction was affected by Reionization, it would tell us something about the early Universe that is very difficult to probe otherwise,” he concludes.
The next step? THE AI help to identify more galaxies of this type, assures the researcher, so that it is possible to know more about the beginnings of the Universe.
