Dark matter has its portrait taken

William Atkins
Tuesday, 10 January 2012 23:58

Science - Space

An international team of astronomers has taken images that show large-scale clumps of dark matter throughout the universe. These images, the largest so far taken, help scientists learn more about dark matter, and its role in making up most of the mass of the universe.

The team used the Canada-France-Hawaii Telescope, which is located near the summit of Mauna Kea on the Big Island of Hawaii and forms one of the observatories of the Mauna Kea Observatory.

Each image, four in all, shows dark matter extended out approximately one billion light-years and containing about 10 million galaxies.

On average, these galaxies are about 6 billion light-years from us, and represent about half the age of the universe (about 6 billion years out of a total of approximately 13.75 billion)

Although the dark matter cannot directly be seen, the astronomers were able to identify dark mass by how it bends light - using a technique called gravitational lensing. Because dark matter has mass, its gravitational field will bend light as it passes close by.

These images of dark matter are considered to be about 100 times larger than the previous map of dark matter, which was taken by the Hubble Telescope.

The January 10, 2012 Sydney Morning Herald article 'Astronomers make large map of dark matter' describes this largest-ever map of dark matter in more detail.

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