Water has been detected in the most massive galaxy in the early Universe, according to new observations from the Atacama Large Millimeter/submillimeter Array (ALMA). Scientists studying SPT0311-58 found H20, along with carbon monoxide in the galaxy, which is located nearly 12.88 billion light-years from Earth. 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 H20 in a regular star-forming galaxy. The research is published in The Astrophysical Journal.
SPT0311-58 is actually made up of two galaxies and was first seen by ALMA scientists in 2017 at its location, or time, in the Epoch of Reionization. This epoch occurred at a time when the Universe was just 780 million years old—roughly 5-percent 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.
“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.”
Read more at National Radio Astronomy Observatory
Image: These science images show the molecular lines and dust continuum seen in ALMA observations of the pair of early massive galaxies known as SPT0311-58. On left: A composite image combining the dust continuum with molecular lines for H20 and CO. On right: The dust continuum seen in red (top), molecular line for H20 shown in blue (2nd from top), molecular line transitions for carbon monoxide, CO(6-5) shown in purple (middle), CO(7-6) shown in magenta (second from bottom), and CO(10-9) shown in pinks and deep blue (bottom). (Credit: ALMA (ESO/NAOJ/NRAO)/S. Dagnello (NRAO) - License CC BY-SA)