Oxygen first formed in the universe at least 13 billion years ago


Astronomers have spotted a young galaxy far, far away that is loaded with ancient stardust from some of the earliest stars in the universe.

The galaxy is called A2744_YD4, and it's the most distant galaxy ever found by ALMA.

Named A2744_YD4, the surprisingly dusty galaxy is located in the constellation Sculptor, 13 billion light years away.

Evidence of the Universe's first stars was just found in a galaxy far, far away. All of the gravity around Pandora's Cluster helped astronomers see A2744_YD4 by magnifying the light, a process known as gravitational lensing. This was possible by looking at a galaxy called A2744_YD4 which appeared to us as if the universe was in extreme infancy.

Scientists were surprised to find a high content of dust in the galaxy along with a rapid rate of star formation.

"The chemical elements in these [cosmic dust] grains are forged inside stars and are scattered across the cosmos when the stars die, most spectacularly in supernova explosions, the final fate of short-lived, massive stars", the European Southern Observatory, which operates ALMA, said in a statement.

This is the most distant, and hence earliest, detection of oxygen in the Universe, surpassing another ALMA result from 2016. "Determining the timing of this "cosmic dawn" is one of the holy grails of modern astronomy, and it can be indirectly probed through the study of early interstellar dust".

As per the observation and the study conducted so far on the young galaxy, it is believed that it consists of dust equivalent to about 6 million times the mass of the sun, while the total number of stars in that galaxy is about 2 billion times the mass of our sun. "Remarkably, the required time is only about 200 million years - so we are witnessing this galaxy shortly after its formation". Scientists believe that studying the heavy elements from this era would provide essential clues to what triggered reionization and what led to the birth of the first galaxies about 100 million years after the Big Bang.

These distant discoveries can tell scientists a great deal about how stars formed in the early universe.

That means stars began to form 200 million years before the light from A2744_YD4 reached ALMA's telescope array, making the stardust that astronomers can see the remnants of some of the earliest stars in the universe, the researchers said.

It was through observations of the surprisingly large amounts of such interstellar dust in A2744_YD4 that the team detected the glowing emission of ionised oxygen. You, the screen you are now reading these words on, the chair you are sitting on and the planet you live on are all the end result of 13.8 billion years of cosmic evolution - a process that began with the birth and death of the first stars. In the earliest days of the universe, when the first generations of stars had not yet exploded, there wasn't much stardust around yet. Says Laporte, "Further measurements of this kind offer the exciting prospect of tracing early star formation even further back into the early universe".