Astronomers ready to 'push cosmic horizons' after confirming detection of oldest galaxy

Astronomers were recently able to detect the earliest galaxy known to mankind with the help of the Atacama Large Millimeter/submillimeter Array (ALMA) telescope. The universe, which is said to be made up of some two trillion galaxies, possesses one galaxy that scientists believe to be the oldest one till date, according to Sputnik. 

It lies almost 13.5 billion light-years away, and came into existence merely 367 million years before the big bang. Named GHZ2/GLASS-z12, it was first spotted by the James Webb Space Telescope (JWST) last year, but scientists decided to wait until they could confirm via another space instrument.

“These deep ALMA observations provide robust evidence of the existence of galaxies within the first few hundred million years after the big bang, and confirm the surprising results from the Webb observations,” said Jorge Zavala from the National Astronomical Observatory of Japan.

Previously, the record of the oldest galaxy was held by GN-z11 which is estimated to have been formed about 400 million years after the big bang. The ALMA telescope, with its 66 12-meter-long antennas, pointed at the newly detected galaxy and discovered an oxygen emission line in the vicinity. After a deeper analysis, it was found that the galaxy was related to GHZ2/GLASS-z12.

Researchers explain how the galaxy was detected

Oxygen emission is a key component that helps astronomers look into distant galaxies. “We performed detailed tests on the observations to confirm that this really is a robust detection, and it is very difficult to explain through any other interpretation,” said Tom Bakx, an astronomer at Japan’s Nagoya University and one of the team leads at the National Astronomical Observatory.

The fact that a galaxy like GHZ2/GLASS-z22 possessed oxygen at such an earlier point of the universe shows a vague timeline of the earliest stars that are yet to be explored by scientists. “The combined power of Webb and the radio telescope array ALMA give us the confidence to push our cosmic horizons ever closer to the dawn of the Universe,” Zavala said.