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Astronomers have detected a galaxy located 13 billion light-years from Earth, making it the most
distant such object on record. The find, described in a paper to be published in the Astrophysical Journal, should
help scientists better understand the so-called cosmic Dark Ages, when the universes first galaxies and quasars transformed
opaque hydrogen into the transparent cosmos that exists today.
The record-breaking galaxy is so far away and so dim that the astronomers needed considerable help
to observe it. The galaxy cluster known as Abell 2218, which is very massive and located between the galaxy and Earth, bent
and magnified its light. "As we were searching for distant galaxies magnified by Abell 2218, we detected a pair of strikingly
similar images whose arrangement and color indicate a very distant object," explains lead author Jean-Paul Kneib of the California
Institute of Technology. The data collected by NASAs Hubble Space Telescope and the W. M. Keck Telescopes in Hawaii signal
that the objects redshift, which measures the shift of light to longer wavelengths and reveals its distance from Earth, lies
between 6.6 and 7.1. "The galaxy we have discovered is extremely faint, and verifying its distance has been an extraordinarily
challenging adventure," says Kneib. "Without the 25 times magnification afforded by the foreground cluster, this early object
could simply not have been identified or studied in any detail at all with the present telescopes available."
Tooken from Sientific American: www.sciam.com
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