Missing dark matter found
4 February 2005
by Richard
Conan-Davies
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The missing matter in the Universe may have been discovered by the Chandra x-ray telescope run by NASA and Harvard University. Astronomers looking at a region of space near a galaxy called Mkn 421 some 400 million light years from Earth shows a very low density spread of gas. The team, led by Fabrizio Nicastro, determined that this could account for the missing matter. Dr. Nicastro explained that "These clouds have defied detection because of their predicted temperature range of a few hundred thousand to a million degrees Celsius, and their extremely low density. Evidence for this warm-hot intergalactic matter (WHIM) had been detected around our Galaxy" "Combining these data with observations at ultraviolet wavelengths enabled the team to estimate the thickness (about 2 million light years) and mass density of the clouds." Why an x-ray telescope? Well the team were looking at how x-rays increase and decrease in intensity as they passed through the thinly spread interstellar gas. This allows them to calculate how much matter might be in the universe. |
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