UMass researchers catch glimpse of ancient galaxy

UMass researchers detailed their observations of a galaxy that can be seen from Earth only as it was 12.4 billion years ago — about 1.3 billion years after scientists believe the universe was born. UMass-Amherst

Researchers at the University of Massachusetts Amherst have caught a detailed glimpse deep into the history of the universe, using a novel telescope to spot an ancient galaxy with a surprising makeup that is raising new questions about what happened after the big bang.

In a study set for publication in The Astrophysical Journal, UMass astronomer Alexandra Pope and her colleagues detailed their observations of a galaxy that can be seen from Earth only as it was 12.4 billion years ago — about 1.3 billion years after scientists believe the universe was born.

Astronomers had seen the galaxy, named MACS0717_Az9, before. But when Pope’s team looked at it through the Large Millimeter Telescope in Mexico, they made a surprising finding: It had been making many more stars than anyone could have seen through its dusty composition.

The sheer amount of dust in the galaxy came as a surprise to researchers, who are wondering where it all came from. Such dust is usually made up of metals that later formed planets and oceans — and here, the makings of life. Researchers are trying to understand its origins.

“We want to know how those metals were built up over cosmic time, because that’s what our solar system and our Earth and we as people are made up of,” Pope said Thursday. “It’s sort of our earliest origin.”

Galaxies like the one spotted in the study could help scientists learn more about how the material is formed. Generally, it is believed that the dust is formed throughout the long lifetimes of stars, but the galaxy from the UMass study is relatively small and young.

The next step toward answering the question will be to look at more galaxies from the early universe to see whether there are others like the one UMass researchers looked at.

That will get easier as early as next year, when Pope’s colleague installs a new imaging system on the telescope that will allow astronomers to complete five years’ worth of similar observations in just over a week, the university said.

If researchers find more galaxies like the one from the recent study, it could challenge attitudes about how galaxies, stars, and complicated atoms were formed.

“Is this guy an oddball? Is this a rare thing?” Pope asked. “Or is this just normal, and most galaxies have more dust than we expect?”