In space research, the theory has persisted for about 40 years that galaxies Dark matter own. This matter is not visible, but science firmly assumes that it exists, since many things could not be explained without it. However, new findings are causing the traditional view to falter.
Galaxies without dark matter possible
The current research into the relationship between galaxies and dark matter began in 2018, according to UCI News. Back then, researchers Shany Danieli and Pieter van Dokkum made an exciting discovery: they observed two galaxies that appeared to exist without most of their dark matter. Even then, this caused a stir in science.
This discovery formed the basis of a new study using computer simulations. These visualize the history of the universe over a distance of 60 million light years from the Big Bang to the present day – not unlike another, much more extensive simulation of the universe. The research team found seven galaxies almost entirely without dark matter. They were created by collisions with neighboring galaxies that were 1000 times more massive. As a result of these collisions, they lost much of their matter.
Science is upside down
The researchers discovered the new findings purely by accident. They emphasize that the computer model used was not developed so that they could create galaxies without dark matter. The collisions required for this were not explicitly implemented. Nevertheless, it happened within the simulation. This only strengthens the model in its expressiveness all the more.
In any case, the new results suggest that such galaxies should actually occur quite frequently in space, especially in the vicinity of more massive galaxies. For science, however, they also pose a challenge for the previously known model:
“The observation that there are galaxies free of dark matter is a little worrying to me. We have a successful model, developed over decades of hard work, in which most of the matter in the cosmos is dark. However, there is always a chance that nature has fooled us.”
James Bullock, Astrophysicist at UCI (University of California, Irvine)
The search for evidence
The standardized model of dark matter does not yet have to be left behind. And there is no 100% certainty that the new model is really correct. The theory about the processes is in place, but now practice has to help.
The researchers hope that their investigation will now encourage others to actually look for very real examples in the night sky. “A real test will show whether these things exist with the frequency and general properties that fit our predictions,” Bullock said.
One can only hope that the computer model can soon be concretely proven. In any case, it remains exciting, especially in this field of research: Scientists may have also observed luminous dark matter.
Source: “Galaxies lacking dark matter produced by close encounters in a cosmological simulation” (2022, Nature Astronomy), UCI News