Huge new survey to shine light on dark matter
Huge new survey to shine light on dark matter
European Southern Observatory Press Release
Posted on 11 July 2015 by Astronomy Now
The first results have been released from a major new dark matter survey of the southern skies using ESO’s VLT Survey Telescope (VST) at the Paranal Observatory in Chile. The VST KiDS survey will allow astronomers to make precise measurements of dark matter, the structure of galaxy halos, and the evolution of galaxies and clusters. The first KiDS results show how the characteristics of the observed galaxies are determined by the invisible vast clumps of dark matter surrounding them.
Around 85% of the matter in the Universe is dark, and of a type not understood by physicists. Although it doesn’t shine or absorb light, astronomers can detect this dark matter through its effect on stars and galaxies, specifically from its gravitational pull. A major project using ESO’s powerful survey telescopes is now showing more clearly than ever before the relationships between this mysterious dark matter and the shining galaxies that we can observe directly.
The project, known as the Kilo-Degree Survey (KiDS), uses imaging from the VLT Survey Telescope and its huge camera, OmegaCAM. Sited at ESO’s Paranal Observatory in Chile, this telescope is dedicated to surveying the night sky in visible light — and it is complemented by the infrared survey telescope VISTA. One of the major goals of the VST is to map out dark matter and to use these maps to understand the mysterious dark energy that is causing our Universe’s expansion to accelerate.
The best way to work out where the dark matter lies is through gravitational lensing — the distortion of the Universe’s fabric by gravity, which deflects the light coming from distant galaxies far beyond the dark matter. By studying this effect it is possible to map out the places where gravity is strongest, and hence where the matter, including dark matter, resides.
More:
http://astronomynow.com/2015/07/11/huge-new-survey-to-shine-light-on-dark-matter/
