Scientists detect water in the biggest galaxy of early universe

Scientists have detected traces of water and carbon monoxide in the biggest known galaxy of the early universe, according to a newly published research in The Astrophysical Journal. 

The study was spearheaded by astronomer Sreevani Jarugula at the University of Illinois, using the Atacama Large Millimetre Array (ALMA) telescope. While water molecules aren’t particularly rare in space, the research stands out for being the most detailed molecular gas study of galaxies in the ‘early’ universe, to date.

The galaxy, technically named SPT0311-58, is 12.88 billion light years away from Earth. This puts it in the early universe phase, with the creation event pegged to be 13.8 billion years in the past. 

Describing the discovery and its significance, Jarugula said in her research publication, “Using high-resolution ALMA observations of molecular gas in the pair of galaxies known collectively as SPT0311-58 we detected both water and carbon monoxide molecules in the larger of the two galaxies. Oxygen and carbon, in particular, are first-generation elements, and in the molecular forms of carbon monoxide and water, they are critical to life as we know it.”

The study is said to be key to understanding how elements known to create and support life, such as H2O, were formed in the early years of the universe. 

“This galaxy is the most massive galaxy currently known at high redshift, or the time when the Universe was still very young. It has more gas and dust compared to other galaxies in the early Universe, which gives us plenty of potential opportunities to observe abundant molecules and to better understand how these life-creating elements impacted the development of the early Universe,” adds Jarugula.

The study also seeks to explain the reasons why the conditions of the early universe facilitated the formation of stars, and continues to do so. It is also incidentally the farthest discovery of the water molecule to date, which makes the research even more significant in terms of how far away and how early may life have flourished in worlds that so far remain undiscovered.

“This study not only provides answers about where, and how far away, water can exist in the Universe but also has given rise to a big question: How has so much gas and dust assembled to form stars and galaxies so early in the Universe? The answer requires further study of these and similar star-forming galaxies to get a better understanding of the structural formation and evolution of the early Universe,” Jarugula further adds in her study.

The galaxy pair was first discovered through ALMA for the first time in 2017, in the Epoch of Reionization. The latter is known as the period during which the first stars and galaxies started to take shape from the dense, giant fog of gas that the universe was in its initial years. 

The galaxies are being studied within their initial billion years of existence, and may hold key answers to understanding the possibility of life even in the primordial universe.