Scientists working with Chile’s Atacama Large Millimeter/submillimeter Array (ALMA) have observed a galaxy that forms stars at an unprecedented rate, a new study published in Nature reports.
The distant “Monster Galaxy” — known as COSMOS-AzTEC-1 — came about roughly 2 billion years after the Big Bang. While it appears normal at first glance, it is unique because it generates over a thousand Suns worth of gas of stars each year.
That trait is important because, while scientists do not understand early galaxies, the new discovery could shed light on why certain systems form stars so fast.
When studying the new system, astronomers found that the clumpy gas inside of it has a stronger gravitational pull on itself than the force of the galaxy’s rotation from stars and supernovae. In addition, they also discovered it had two extra areas of gas-generating stars, rather than just one dense cloud of material.
“We found that there are two distinct large clouds several thousand light-years away from the center,” said lead author Ken-ichi Tadaki, a researcher at the Japan Society for the Promotion of Science and Japan’s National Astronomical Observatory, according to Space.com. “In most distant starburst galaxies, stars are actively formed in the center. So it is surprising to find off-center clouds.”
A team of international researchers found the galaxy while using ALMA’s 66 radio telescope dishes in the Chilean desert to look for signatures of carbon monoxide gas. Once they discovered it, they created a map based on what they found.
That showed the large, dense gas clumps inside AzTEC-1 are quite unstable and likely burn out within 100 million years of their formation. However, they form stars extremely quickly in that time.
Scientists are still not sure how galaxies like AzTEC-1 manage to build up so much gas before beginning their star formation, but they believe it could be the result of a galactic merger. Even so, as there is no evidence to support that process, more observations need to be done on such systems in the coming years to get a better idea of how they work.
“At this moment, we have no evidence of merger in this galaxy,” added Tadaki, according to Phys.org. “But by observing other similar galaxies with ALMA, we want to unveil the relation between galaxy mergers and monster galaxies.“