Water has been detected in the most massive galaxy pair in the early Universe, according to new observations from the Atacama Large Millimeter/submillimeter Array (ALMA).
Scientists detected water along with carbon monoxide in SPT0311-58 -- made up of two galaxies -- located nearly 12.88 billion light years from Earth.
Water, in particular, is the third most abundant molecule in the universe after molecular hydrogen and carbon monoxide.
SPT0311-58 was first seen by ALMA scientists in 2017 at its location, or time, at a time when the universe was just 780 million years old -- roughly 5 per cent of its current age -- and the first stars and galaxies were being born.
Scientists believe that the two galaxies may be merging, and that their rapid star formation is not only using up their gas, or star-forming fuel, but that it may eventually evolve the pair into massive elliptical galaxies like those seen in the Local Universe.
Detection of these two molecules in abundance suggests that the molecular universe was going strong shortly after the elements were forged in early stars. The new research comprises the most detailed study of molecular gas content of a galaxy in the early universe to date and the most distant detection of water in a regular star-forming galaxy.
The research is published in The Astrophysical Journal.
"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," said Sreevani Jarugula, an astronomer at the University of Illinois and the principal investigator on the new research.
"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," Jarugula added.
Previous studies of galaxies in the local and early Universe have correlated water emission and the far-infrared emission from dust.
Studying the first galaxies to form in the Universe helps scientists to better understand the birth, growth, and evolution of the Universe, and everything in it, including the Solar System and Earth.