October 14, 2011 20:17
Dark matter in the center of galaxies "packaged" more tightly than predicted many of the existing theories. This conclusion was made by astronomers studying distant galaxy clusters images, obtained in the framework of CLASH (Cluster Lensing And Supernova survey with Hubble — an overview of supernovae and study of the phenomenon of gravitational lensing with the telescope "Hubble"). Briefly research results are presented in the press release NASA.
Dark matter — it is not detected experimentally substance, which is involved in the gravitational interaction, but does not participate in the electromagnetic — accordingly, it can not be detected by direct observation. The share of dark matter accounts for about 23 percent of the mass in the universe (with 72 percent "responsible" dark energy, and the "normal" matter accounts for only 4 percent).
The project CLASH scientists study dark matter by gravitational lensing. It is based on the curvature of the path of light passing near the source of a large mass. Because of this phenomenon images of distant galaxies are often distorted, and these distortions more than they should have been the case if all the mass in the universe was concentrated only in the visible objects. It is believed that the "extra" weight "hidden" in the dark matter.
Located in orbit telescope "Hubble" allows astronomers to see distant galaxies, which can not be observed from Earth. At the moment, astronomers quality photos 6 of 25 selected for the project CLASH galaxy clusters. The illustration is an accumulation of news called MACS J1206.2-0847, or MACS 1206. Age of its constituent galaxies is estimated between 9 and 12 billion years. Preliminary analysis of the collected "Hubble" information suggests that the density of dark matter in galaxies is higher than previously thought. This conclusion, in turn, is not consistent with a hypothesis to explain the appearance of these clusters — new data suggest that they were formed earlier than was previously assumed.
In the summer of 2011, four scientists became laureates Cosmological Foundation Prize Peter and Patricia Gruber half million dollars for the development of a model distribution of dark matter in the universe.