Astronomers Find Early Star-Producing Galaxy, Challenge Theories On Cosmic Development

A team of astronomers are reporting they've discovered the earliest known star-making galaxy in the universe.

The researchers, including several from the California Institute of Technology (Caltech), have detected a massive, dust-filled galaxy believed to have been creating stars when the cosmos was only about 880 million years old.

The galaxy in question is about as big as our own Milky Way, but delivers about 2,000 times more stars, which equals a mass of about 2,900 suns per year.

That many stellar births matches the highest production rate anywhere, which was why the new galaxy's discoverers dubbed it a "maximum-starburst" galaxy.

"Massive, intense starburst galaxies are expected to only appear at later cosmic times," Dominik Riechers, who led the research while a senior research fellow at Caltech, was quoted saying by Science Daily. "Yet, we have discovered this colossal starburst just 880 million years after the Big Bang, when the universe was at little more than 6 percent of its current age."

Now an assistant professor at Cornell, Riechers is the first author of a paper that describes the findings in the April 18 issue of the journal Nature.

The long-held belief among scientists has been that the first galaxies were small and produced stars at a modest rate.

Then, when the universe was a couple of billion years old, the smaller galaxies began to merge into larger galaxies with enough accumulation of gas and dust to become starburst galaxies --- in other words, prolific star factories.

The prevalent thinking was that those abundant star-makers showed up to the astronomical game a couple billion years after the Big Bang.

While the discovery of the one galaxy isn't enough to overturn current theories of galaxy formation, finding similar galaxies could challenge those theories, the research team indicated.

At the very least, theories will have to be modified to explain how the newly-found galaxy, named HFLS3, formed, Riechers said.

The astronomers found HFLS3 brimming with molecules like carbon monoxide, ammonia, hydroxide, and water --- a telltale sign of active star creation.

"This galaxy is just one spectacular example, but it's telling us that extremely vigorous star formation was possible early in the universe," says Jamie Bock, professor of physics at Caltech and a coauthor of the paper.