Sunday, August 21, 2011

The Universe Video~ Astronomers Unveil Most Complete 3-D Map of Local Universe





Astronomers Unveil Most Complete 3-D Map of Local Universe

Astronomers unveiled the most complete 3-D map of the local universe (out to a distance of 380 million light-years) ever created. Taking more than 10 years to complete, the 2MASS Redshift Survey also is notable for extending closer to the Galactic plane than previous surveys - a region that's generally obscured by dust. The 2MASS Redshift Survey is a complete new look at the local universe - particularly near the Galactic plane. A galaxy's light is redshifted, or stretched to longer wavelengths, by the expansion of the universe. The farther the galaxy, the greater its redshift, so redshift measurements yield galaxy distances - the vital third dimension in a 3-D map. 2MRS chose galaxies to map from images made by the Two-Micron All-SkySurvey (2MASS). This survey scanned the entire sky in three near-infrared wavelength bands. Near-infrared light penetrates intervening dust better than visible light, allowing astronomers to see more of the sky. But without adding redshifts, 2MASS makes only a 2-D image.