UH team discovers distant galaxy

Advertiser Staff

An international team led by astronomers from the University of Hawai'i is reporting the discovery of a galaxy they say provides the earliest glimpse of the formation of galaxies and stars.

The newly discovered galaxy shows the universe when it was about 780 million years old, about 80 million years earlier than previously observed, said UH Professor Esther Hu, who led the team.

"You want to catch galaxies in their infancy and see how they develop," Hu said. "Scaling the age of the universe to a person's lifetime, we're showing you baby pictures. The last galaxy snapshot showed a toddler just past his fourth birthday. This one is 3 1/2."

Team members had previously used one of the Keck telescopes on Mauna Kea to find what had been the most distant galaxy, an object whose light took about 15.3 billion years to reach Earth.

To reach fainter and more distant galaxies, Hu and her colleagues used massive cluster galaxies as a "gravitational lens" to further amplify the light. The astronomers used the cluster Abell 370, which is 6 billion light years away and whose core contains the mass of several hundred galaxies, to magnify light from a galaxy behind the cluster that is 15.5 billion light years distant.

According to the generally accepted theory, the universe started with the Big Bang some 14 billion to 16 billion years ago. Over the next nearly half-billion years, cold gas began to assemble into the first galaxies.

Until now, the earliest probes of the universe have been quasars, which are extremely luminous distant objects, believed to be powered by black holes.