AMHERST — It was a discovery as novel as photographing yeti footprints, according to the team of researchers that included UMass assistant professor Kate Whitaker: Using telescopes in the mountains of Chile, astronomers detected a “monster” galaxy billions of light-years away.
The galaxy stood out for “the combined fact that we discovered something so early in the universe, and that it’s so massive,” said Whitaker, who specializes in early galaxy formation and evolution.
“Generally, you don’t form things that big that early,” she said. “It’s not to say that it’s impossible, but it’s sort of at the limits of what our models predict currently.”
Whitaker worked on a team led by UMass alumna Christina Williams, now a postdoctoral fellow at the University of Arizona. The astronomers estimate that light from the galaxy took 12.5 billion light-years to reach Earth, placing it in a time where the universe was only 10 percent of its current age.
Despite the rarity of the find, the team spotted the galaxy by accident. While studying massive dead galaxies in the early universe, the astronomers detected the galaxy using data from the Atacama Large Millimeter Array of 66 radio telescopes in the mountains of Chile. The galaxy, which is obscured by dust, had not been visible under any other wavelength of light they had used, and even now, the astronomers have only spied traces of it.
Now that the team knows the galaxy exists, the next step is understanding how it was formed, Whitaker said. The discovery signifies “the tip of the iceberg” of how many similarly hidden galaxies may exist in the universe, she added — despite the rarity of the find, it’s possible that there are many more hidden in the universe.
“Their mere existence means that our models have to explain why they’re there,” Whitaker said. “Why do we see them, why do they exist, how are they there so early?”
Jacquelyn Voghel can be reached at jvoghel@gazettenet.com.
