Chuck Bednar for redOrbit.com – @BednarChuck
Using the ESO’s Very Large Telescope, a team of scientists has collected the best observational evidence to date of first-generation stars born out of the primordial material produced by the Big Bang. This, according to research accepted for publication by The Astrophysical Journal.
Since oxygen, nitrogen, carbon and other heavier chemical elements were all originally formed in stars, these ancient stars (also known as Population III stars) would have been formed from the only elements that predate the existence of stars: hydrogen, helium and lithium.
These stars, the authors explained in a statement, would have been at least several hundred times more massive than the Sun and exploded as supernovae after roughly two million years. Previous attempts to find physical proof of the existence of Population III stars had been inconclusive.
Distant galaxy possesses characteristics of Population III stars
The authors of this new study, however, used the VLT to look back approximately 800 million years to a period in the history of the universe known as “reionization”. Instead of focusing their efforts on a deep analysis of one small region of the sky, however, they broadened their scope to produce what is being called the widest survey of very distant galaxies to date.
Using the telescope, the research team found and confirmed multiple surprisingly bright, very young galaxies, including one which was the brightest galaxy ever observed at this stage in the universe. Dubbed CR7, the galaxy had a bright pocket that contained ionized helium emissions but no trace of heavier elements. The authors believe that the discovery represents the first-ever solid evidence of Population III star clusters with ionized gas in the early universe.
“The discovery challenged our expectations from the start, as we didn’t expect to find such a bright galaxy,” said lead author David Sobral from the Institute of Astrophysics and Space Sciences, the University of Lisbon in Portugal and Leiden Observatory in the Netherlands.
“Then, by unveiling the nature of CR7 piece by piece, we understood that not only had we found by far the most luminous distant galaxy, but also started to realize that it had every single characteristic expected of Population III stars,” he added. “Those stars were the ones that formed the first heavy atoms that ultimately allowed us to be here. It doesn’t really get any more exciting than this.”
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