3-D Map Gives Accurate Distance Of Galaxies

Scientists have invented a new 3-D map of the universe which gives accurate measurements of the distance among galaxies and provide more clues about the dark energy.

Scientists from the University of Arizona and the Harvard-Smithsonian Center for Astrophysics have invented the map by using data from the Sloan Digital Sky Survey, or SDSS-III. It took two full years for scientists to collect and compile the data from the Baryon Oscillation Spectroscopic Survey, or Boss, one of the SDSS-III's four surveys of the sky.

Boss is producing the most detailed map of the universe ever made, using a new custom-designed spectrograph of the SDSS 2.5-metre telescope at Apache Point Observatory in New Mexico. The map contains information about more than 250,000 galaxies; some of these galaxies are so distant that their light has travelled more than six billion years to reach earth - nearly half the age of the universe.

According to Xiaohui Fan, a professor of astronomy at the University of Arizona's Steward Observatory, galaxies are distributed along the frozen wave pattern, so by looking at these patterns expanding over time, "we are measuring how the universe is expanding. This pattern is used as a standard ruler, a cosmic yardstick so to speak."