Dark matter can be an even bigger mystery than previously thought. Dark matter is thought to represent a significant percentage of the mass of the universe – yet it is almost impossible to study, let alone observe.
Physicists have been forced to study how dark matter bends light between distant sources, such as a galaxy and the observer, an effect called the “gravitational lens.” Thus, the higher the concentration of dark matter, the more pronounced the effect.
In other words, we are missing a key ingredient
But when a team of European researchers analyzed data from the Hubble Space Telescope and Southern Observatory’s Very Large Telescope, they found that the gravitational lensing effect around massive structures called “galaxy clusters” was ten times stronger than its predecessor. provided by simulations.
“We have done a lot of testing of the data in this study and we are sure that this mismatch indicates that a certain physical ingredient is missing either from simulations or from our understanding of the nature of dark matter,” said Massimo Meneghetti of INAF-Observatory of Astrophysics and Space Science of Bologna in Italy and lead author of a paper on research published in the journal Science in an ESA statement.
“One possible source of this discrepancy is that we are likely to lack some key physical elements in the simulations,” Meneghetti said in a NASA statement. To conduct their research, Meneghetti’s team produced a “dark matter map” using observations from a sample of three groups of massive galaxies.
So they discovered something unexpected: smaller-scale images nestled in larger lens distortions in the core of each group of galaxies. In other words, the gravitational lensing effect was significant, leading them to believe that they encountered dense concentrations of dark matter.
The discrepancy highlights how little we know about the mysterious things that seem to make up most of the known universe.