The early universe was a primordial 'fog' of hydrogen atoms.
Credit: ESO
PARIS: Astronomers have found a distant galaxy from the universe's infancy, using "photons emitted less than 600 million years after the Big Bang," they wrote in Nature.
European astronomers on Wednesday said a galaxy born in the childhood of the universe lies at least 13 billion light years away, making it the remotest object ever observed.
Light from the galaxy UDFy-38135539 that astronomers observe today was emitted when the universe was only 600 million years old and mired in a primordial 'fog' of hydrogen atoms, they said.
The most distant object
It has taken 13.1 billion years, travelling at 300,000 km (186,000 miles) per second, for this smudge of infant light to arrive. The study used the Very Large Telescope in Chile's Atacama Desert to measure the galaxy's redshift.
The more distant a light source is, the longer its wavelength stretches. In other words, a light that appears to be receding from the observer shifts more towards the red part of the optical spectrum.
In this case, the galaxy's redshift was 8.6, making it the most distant object ever observed by spectroscopy.
Clearing the 'fog'
The previous documented record, in 2009, was a redshift of 8.2 caused by a gamma-ray burst of a super-massive star. An object at a redshift of 10 was once reported but has never been confirmed.
"Measuring the redshift of the most distant galaxy so far is very exciting in itself, but the astrophysical implications of this detection are even more important," said Nicole Nesvadba of France's Institut d'Astrophysique Spatiale.
"This is the first time we know for sure that we are looking at one of the galaxies that cleared out the fog which had filled the very early universe."
Astronomers believe the universe originated in a superheated-flash around 13.7 billion years ago called the Big Bang, and started to expand.
After the cosmos had cooled a little, electrons and protons teamed up to form hydrogen, which for hundreds of millions of years filled the universe.
