The Dark Matter Survey
An international team of astronomers used the above method to map the presence of dark matter in the night sky. They analyzed data collected over a five-year period from the Canada-France-Hawaii Telescope (CFHT) on the island of Mauna Kea. Images from some 10 million galaxies, typically six billion light years from Earth, were evaluated. (A light year is a measure of distance not time — it is the distance light travels in one year, which is about 6 trillion miles or 10 trillion kilometers.)
Led by Dr. Catherine Heymans, of the University of Edinburgh, Scotland, and Associate Professor Ludovic Van Waerbeke, of the University of British Columbia, Vancouver, Canada, the team studied images of galaxies recorded by the CFHT MegaCam wide-field camera in four regions of the night sky. From distortions in galaxy images, astronomers mapped, as CFHT news put it, an “intricate cosmic web of dark matter” a staggering one billion light years across.
“What we see here is very similar to the (computer) simulation,” Van Waerbeke later told Scientific American. “Dark matter is concentrated in lumps and the rest stretches in filaments.”
As predicted, these so-called lumps were found where galaxies cluster together — confirming dark matter’s role as the cosmic glue which holds galaxies and clusters of galaxies together.
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