| dethalternate | Date: Thursday, 07-May-2015, 11:58 AM | Message # 1 |
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| Galaxy EGS-zs8-1 sets a new distance record. It’s so far away the light we receive left the galaxy over 13 billion years ago, and it is just arriving now.
An international team of astronomers, led by Yale University and the University of California scientists, pushed back the cosmic frontier of galaxy exploration to a time when the universe was only five percent of its present age of 13.8 billion years.
The team discovered an exceptionally luminous galaxy – called EGS-zs8-1 – more than 13 billion years in the past and determined its exact distance from Earth using the combined data from NASA’s Hubble and Spitzer space telescopes, and the Keck I 10-meter telescope at the W. M. Keck Observatory in Hawaii. These observations confirmed it to be the most distant galaxy currently measured, setting a new record. The galaxy existed so long ago, it appears to be only about 100 million years old. The findings were published in Astrophysical Journal Letters today (May 5, 2015).
Galaxy EGS-zs8-1 is one of the brightest and most massive objects in the early universe and was originally identified based on its particular colors in images from NASA’s Hubble and Spitzer Space Telescopes.
Pascal Oesch of Yale University is the lead author of the study. He said:
While we saw the galaxy as it was 13 billion years ago, it had already built more than 15 percent of the mass of our own Milky Way today. But it had only 670 million years to do so. The universe was still very young then.
The new distance measurement also enabled the astronomers to determine that EGS-zs8-1 was still forming stars very rapidly, about 80 times faster than our galaxy today.
Only a handful of galaxies currently have accurate distances measured in this epoch of the universe and none younger than this.
Pieter van Dokkum of Yale University is second author of the study. He said:
Every confirmation adds another piece to the puzzle of how the first generations of galaxies formed in the early universe. Only the largest telescopes are powerful enough to reach to these large distances.
The discovery was only possible thanks to the relatively new MOSFIRE instrument on the Keck I telescope, which allows astronomers to efficiently study several galaxies at the same time.
The observations see EGS-zs8-1 at a time when the universe was undergoing very important changes: the hydrogen between galaxies was transitioning from a neutral to an ionized state.
Read more/full article/source - http://earthsky.org/space/scientists-measure-most-distant-galaxy-yet
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