Astronomers Discover Most Distant Galaxy Yet
A newly discovered galaxy, dubbed EGSY8p7, has set a far-flung record. The ancient galaxy is the most distant one humans have yet discovered, sitting some 13.2 billion light-years away from Earth, Space.com reports.
In fact, the galaxy is so far away that astrophysicists observing it from Earth are seeing it as it was less than 600 million years after the Big Bang — which happened some 13.8 billion years ago.
“This is a time when we believe the first galaxies were formed and had a considerable effect on the evolution of the universe,” Guido Roberts-Borsani, a Ph.D. student at University College London who co-authored a paper describing the galaxy, said in a written statement. “Finding galaxies at such an early age is rare and provides us with a unique insight into the conditions that allowed these objects to form. We are looking at the very first moments of galaxy formation.”
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Astrophysicists used the W. M. Keck Observatory in Hawaii not only to measure how far away the galaxy is located, but also to date the galaxy by detecting its Lyman-alpha emission line — a signature of hot hydrogen gas that can reveal a galaxy’s age since it’s heated by the galaxy’s newborn stars.
The researchers said they were surprised even to be able to detect the Lyman-alpha emission line from so far away.
“We frequently see the Lyman-alpha emission line of hydrogen in nearby objects as it is one of most reliable tracers of star-formation,” Dr. Adi Zitrin, an astrophysicist at the California Institute of Technology and lead author of the paper, said in a separate statement. “However, as we penetrate deeper into the universe, and hence back to earlier times, the space between galaxies contains an increasing number of dark clouds of —> Read More