Astronomers have discovered a surprisingly large reservoir of molecular gas in a group of galaxies about 24.5 billion light years away, according to new research published this week in the journal Astrophysical Journal Letters.
This so-called protocluster, known as SPT2349-56, is a region of the early universe where a cluster of galaxies is just beginning to form.
Galaxy clusters are the largest structures in the universe and understanding their formation is a major goal of scientists. Protoclusters, like SPT2349-56, offer a unique window into this process, allowing astronomers to observe galaxies as they come together in a dense environment.
This new study, led by researchers at Dalhousie University and the University of British Columbia, focuses on the molecular gas within SPT2349-56, which they found to be 75 per cent higher than previously thought. Molecular gas, primarily hydrogen, is the raw material for star formation, which plays a critical role in galaxy evolution.
The team used the Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility in Chile, and an array of antennas that captured lower-resolution data to detect a significant amount of molecular gas that was "invisible" in the higher-resolution ALMA images. In essence, the high-resolution observations allowed scientists to pinpoint individual galaxies, while the lower-resolution data revealed the bigger picture — the extended gas that connects these galaxies and fuels the development of stars.
Dr. Scott Chapman, a Killam professor in astrophysics at Dalhousie, co-led the paper. The discovery of this hidden gas reservoir could be the key to understanding the intense star formation activity observed in SPT2349-56, which produces stars roughly 10,000 times faster than our Milky Way.
Media Contact:
Alison Auld, Senior Research Reporter
Dalhousie University
Email: alison.auld@dal.ca