Astronomers have announced the most distant detection of water in the universe. A team using the Atacama Large Millimeter/submillimeter Array (ALMA) has observed the precious molecule – an element necessary for life as we know it – in galaxy SPT0311-58. This massive star-forming galaxy is located 12.88 billion light-years from Earth, which means the universe was less than 1 billion years old when the light from these water molecules was emitted.
The team has reported the farthest detection of H20 in a normal star-forming galaxy in The Astrophysical Journal. The galaxy is believed to be a merger system made of two galaxies colliding. The gravitational dance is pushing gas together, creating lots of new stars, and among the stars, interesting chemistry is taking place such as the formation of water and carbon monoxide molecules.
“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,” lead author Dr Sreevani Jarugula from the University of Illinois said in a statement.
“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,” Dr Jarugula added.
Water is the third most common molecule in the cosmos. The first one is molecular hydrogen – where two hydrogen atoms pair up – and the second one is carbon monoxide. More complex molecules known as ‘dust’ are heated by UV light and then emit that in the far-infrared portion of the electromagnetic spectrum. Astronomers have discovered that there’s a correlation between water and the emission of dust and can connect this to how many stars are being born in that galaxy.
The light from SPT0311-58 is coming from an epoch of the universe we still do not fully understand, and this discovery tells us that water was already a major player early on. It is an important piece of the puzzle that can help us understand what was going on in the early universe.
“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.”
ALMA continues to push the envelope on how far back into the Universe we can study.