The first image of a dark matter “bridge”, believed to form the links between galaxies, has been captured by astrophysicists in Canada. Researchers at the University of Waterloo used a technique known as weak gravitational lensing to create a composite image of the bridge. Gravitational lensing is an effect that causes the images of distant galaxies to warp slightly under the influence of an unseen mass, such as a planet, a black hole, or in this case, dark matter. Their composite image was made up of a combination of combined lensing images taken of more than 23,000 galaxy pairs, spotted 4.5 billion light-years away. This effect was measured from a multi-year sky survey at the Canada-France-Hawaii Telescope. These results show that the dark matter filament bridge is strongest between systems less than 40 million light years apart, and confirms predictions that galaxies across the Universe are tied together through a cosmic web of the elusive substance. Dark matter is a mysterious element said to make up around 84 per cent of the Universe. It’s known as “dark” because it doesn’t shine, absorb or reflect light, which has traditionally made it largely undetectable, except through gravity and gravitational lensing. Evidence for the existence of this form of matter comes, among other things, from the astrophysical observation of galaxies, which rotate far too rapidly to be held together only by the gravitational pull of the visible matter. Astrophysics has long proposed the Universe’s web of stars and galaxies is supported by a “cosmic scaffolding” made up of fine threads of this invisible dark matter.
Fascinating.. To read the rest of this article, click on the text above.