Dark matter mapping

Dark matter mapping

Abell 2744 is a galactic cluster whose dark matter halo represented more distant galaxies. Scientists compared a snapshot with an imitation of a dark matter lens and found agreement, indicating that modern models of dark matter behavior on a large scale work

Approximately 85% of universal matter is represented by dark matter, whose nature is still unknown to the scientific community. The rest of the matter is in atoms. When studying the evolution of space, scientists notice that dark matter creates gravity and dominates the formation of large structures, such as galactic clusters. Of course, watching her directly is incredibly difficult. It manifests itself only gravitationally.

Usually, galaxies are located in the centers of large areas of dark matter - halos. A unique and powerful probe is gravitational lensing using dark matter. A strong lensing forms a distorted and enlarged image of a particular source, and a weak one - moderate, but systematically deformed forms of background galaxies. Astronomers decided to compare the images of Abell 2744 clusters distorted by gravity, made by the Hubble telescope and two other clusters, and then compare them with the results of computer simulation of dark matter halo. It turned out that they agree on the main points in the predictions of dark matter, where the detailed substructures of galaxies are based on the distribution of dark matter halos, and the total mass and light are related.

There were also differences. The simulation predicted radial distribution of dark matter was different from the real, and the effects of tidal stripping and friction were less than expected. However, researchers believe that these shortcomings will be corrected with more accurate modeling.

Comments (0)