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Astronomers Uncover One of the Youngest and Brightest Galaxies in the Early Universe
02.12.08
NASA�s Hubble and Spitzer space telescopeshave uncovered what may be one of the youngest and brightest galaxies ever seen. Image taken by the Hubble Space Telescope of what may be one of the youngest and brightest galaxies ever seen. Credit: NASA/STScI
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NASA’s Hubble and Spitzer space telescopes, with a boost from a natural “zoom lens,” have uncovered what may be one of the youngest and brightest galaxies ever seen in the middle of the cosmic “dark ages,” just 700 million years after the beginning of our universe.

The detailed images from Hubble’s Near Infrared Camera and Multi-Object Spectrometer (NICMOS) reveal an infant galaxy, dubbed A1689-zD1, undergoing a firestorm of star birth during the dark ages, a time shortly after the Big Bang but before the first stars reheated the cold, dark universe. Images from NASA’s Spitzer Space Telescope’s Infrared Array Camera provided strong additional evidence that it was a young star-forming galaxy in the dark ages. A1689-zD1 may have been one of the galaxies that helped end the dark ages, astronomers said.

Astronomers got a “boost” from a massive cluster of galaxies, named Abell 1689 [image at left], to see the distant galaxy. The hefty cluster acted like a cosmic zoom lens by bending and magnifying the light from the more distant A1689-zD1, a technique called gravitational lensing. A1689-zD1 is so far away, however, it does not show up in the visible-light image taken with Hubble’s Advanced Camera for Surveys [photo at top, right], because its light is stretched to invisible infrared wavelengths by the universe’s expansion. The galaxy does appear in images taken with NICMOS and Spitzer.

A1689-zD1 appears as a grayish-white smudge in the close-up view taken with NICMOS [image at center, right], and as a whitish blob in the Spitzer close-up view [image at bottom, right]. The galaxy is brimming with star birth. It is one of the youngest and brightest galaxies ever discovered. Astronomers estimate that the galaxy is 12.8 billion light-years away. Abell 1689 is 2.2 billion light-years away.

Space Telescope Science Institute
Baltimore, Md.