A simulation of dark matter. Image credit: NASA
Researchers at the University of Bonn and the University of California at Irvine used sophisticated computer simulations to devise a test that could answer a burning question in astrophysics: is there really dark matter? Or does Newton’s gravitational law need to be modified? The new study, now published in the Physical Review Letters, shows that the answer is hidden in the motion of the stars within small satellite galaxies swirling around the Milky Way.
Using one of the fastest supercomputers in the world, the scientists have simulated the matter distribution of the so-called satellite ‘dwarf’ galaxies. These are small galaxies that surround, for instance, the Milky Way or Andromeda.
The researchers focused on a relationship called “radial acceleration relation” (RAR). In disc galaxies, stars move in circular orbits around the galactic centre. The acceleration that forces them to constantly change direction is caused by the attraction of matter in the galaxy. The RAR describes the relationship between this acceleration and the one caused by the visible matter only. It provides an insight into the structure of galaxies and their matter distribution.
“We have now simulated, for the first time, the RAR of ...