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Astronomers revealed that dark matter is actually smoother than previously believed.
STATES CHRONICLE – Scientists argued that it may be more uniform and smoother than they have previously believed. Dark matter is the mass which occupies approximately 27% of the universe. Back in 2013, specialists involved in Europe’s Planck mission have analyzed the oldest source of light in the universe, and they have revealed that dark matter had merged in time, due to gravitational attraction.
Researchers claimed that what appeared to be at the beginning a smooth distribution of dark matter, it has slowly transformed into a dense bulk of matter over time. A new study at the European Southern Observatory’s (ESO) Very Large Telescope (VLT) at the Paranal Observatory in Chile has argued that dark matter is not as bulky as previously thought during the Planck mission.
Massimo Viola, a scientist at the Leiden Observatory in the Netherlands and also the co-leader of the study, has asserted that the latest outcome obtained proved that dark matter which represents a quarter of the universe’s content is smoother than scientists have believed. The international team of specialists used information from the Kilo-Degree Survey (KiDS) at the VLT Survey Telescope to determine the distribution of the dark matter across the universe.
The survey consisted of analyzing in depth about 15 million galaxies grouped into five different clusters of the southern sky, covering approximately 450 square degrees, the equivalent of 2,200 full moons. The gravity of dark matter is able of bending light through a process known as gravitational lensing. Thus, the light emitted by 15 million galaxies could reveal data about the distribution and composition of dark matter.
Scientists have analyzed a variation of such a phenomenon namely cosmic shear or weak gravitational lensing. Cosmic shear designates a subtle aspect which needs to be determined with unerring precision. When galaxy clusters or other large-scale structure identify the formation of this effect known as weak gravitational lensing, then the effect of light-distortion is subtle than believed and harder to be identified compared to gravitational lensing occurring around stars or similar small celestial objects.
The VLT Survey Telescope had captured high-resolution pictures which helped scientists detect the subtle effect of cosmic shear. This study represents the first time when the imagining method is used on a massive portion of the universe to map the dark matter.
Image courtesy of: wikipedia
