Scientists Detect Earliest, Farthest Oxygen Source In Ancient Galaxy

(Photo : Getty Images/Handout) Scientists discovered the oldest source of oxygen to date.

A primordial galaxy born during the cosmic "Dark Ages" was found to be earliest and farthest source of oxygen in the known universe, according to a new study published in the journal Science on June 16.

Study co-author Naoki Yoshida of University of Tokyo explained that an ancient galaxy they have dubbed SXDF-NB1006-2 contained a sizeable amount of oxygen.

“Our results showed this galaxy contains one tenth of oxygen found in our Sun. But the small abundance is expected because the universe was still young and had a short history of star formation at that time,” she said in a statement released Thursday, via Eureka Alert.

The primordial galaxy, located around 13.1 billion light-years away from Earth, was discovered by astronomers using Atacama Large Millimeter/submillimeter Array (ALMA) in Chile and will reportedly be instrumental in clearing up some of the mysteries surrounding the reionization epoch of the universe.

The reionization epoch came 150 million years after the cosmic Dark Ages, which the time that stars have not yet formed, thus there was no light in the universe except for the electrically-charged ions that recombined into atoms about 380,000 years following the Big Bang.

After the Dark Ages, clumps of gas began to break down and form the universe's first galaxies and stars in an era called the reionization.

This epoch is particularly difficult to study as it happened billions of years ago and requires astronomers to analyze the most distant and ancient galaxies and stars, which are only viewable using the most powerful telescopes available today.

However, according to the new study, the discovery of this ancient galaxy could help astronomers figure out the mysteries of reionization, such as which sources of light caused reionization and how the first generation of galaxies were formed.

"The galaxy we observed may be a strong light source for reionization," study lead author Akio Inoue, an astronomer at Osaka Sangyo University in Japan, told Space.com. "SXDF-NB1006-2 would be a prototype of the light sources responsible for the cosmic reionization."

"The source of reionization is a long-standing matter — massive stars or supermassive black holes? This galaxy seems not to have a supermassive black hole, but have a number of massive stars. So massive stars may have reionized the universe," Inoue continued.

The birth of the earliest stars triggered the synthesis of elements such as carbon and oxygen. In the study, researchers focused on the oxygen and dust particles found in the ancient galaxy to see if they can find the key to the secrets of the reionization.

"Seeking heavy elements in the early Universe is an essential approach to explore the star formation activity in that period,” Inoue explained. “Studying heavy elements also gives us a hint to understand how the galaxies were formed and what caused the cosmic reionization."

The scientists will continue to study SXDF-NB1006-2 further using ALMA.

"Higher-resolution observations will allow us to see the distribution and motion of ionized oxygen in the galaxy and provide precious information to understand the properties of the galaxy," said study co-author Yoichi Tamura, of the University of Tokyo.