Ultradiffuse galaxies, or UDGs, are dwarf galaxies with stars scattered across a vast area. Such galaxies have a very low luminosity - it is difficult to detect them in space.
The study was carried out by an international team of scientists led by Laura Sayles, an astronomer from the University of California. The specialists used computer simulations and data on "extinct" ultradiffuse galaxies obtained thanks to powerful telescopes.
“What we found contradicts the theories of galaxy formation, since they usually have to be in clusters or groups, so that sooner or later the influence of neighbors would lead to the outflow of gas and the cessation of star formation,” Phys.org said. Meanwhile, the ultradiffuse galaxies discovered by scientists were isolated from others.
On the left is one of the ultradiffuse galaxies analyzed during the simulation. On the right is an almost transparent image of the DF2 galaxy. Photo: ESA / Hubble
With the help of simulations, scientists have traced the evolution of the "extinguished" UDGs. They learned that many of them were not really formed in clusters and were satellites of more massive systems billions of years ago. Then for some reason (it is not yet known why) they were thrown into an elliptical orbit, so they are now in the distance.
The researchers also report that isolated ultradiffuse galaxies can account for up to 25% of the entire ultradiffuse population. Current observations show a much smaller result. This means that many intriguing galaxies have not yet been noticed by anyone, and it is a matter of time before astronomers do see them.