Team detects 13 billion-year-old phenomenon

Astronomers at UNC celebrated this month an event 13 billion years in the making.

A UNC research team comprising students and professors measured a gamma-ray burst that was more than 13 billion light-years away.

That means the burst began traveling when the universe was 700 million years old - practically infantile in astronomers' eyes.

Daniel Reichart, the UNC professor of physics and astronomy who led the research team, formally announced the discovery at a NASA press conference Monday.

"(It's) very exciting," he said afterwards. "It feels great."

The observation marks the fulfillment of a long-held theory by Reichart and Donald Lamb, a professor of astronomy and astrophysics at the University of Chicago.

In 1999 Lamb and Reichart wrote a paper predicting that gamma bursts occur at extreme distances in space.

Before the discovery last week, the most distant-detected burst was 500 million light-years closer to earth.

The phenomenon, which occurs during the death throes of aging stars, allows for deep-space observation.

"We then can use them as backlights to explore everything in between," Reichart said.

Unfortunately in this case, the proper equipment was not available to conduct the observation.

"It wasn't in the cards this time," Reichart said. "Now that we know they're out there, we and other groups can find them."

There's no indication when gamma-ray bursts will occur, Reichart said, so he and his colleagues must be ready at a moment's notice.

"It's completely random. These are stars that are reaching the end of their lives," he said. "The rate is - approximately is - on average once every few days."

The bursts were observed by the Southern Observatory for Astrophysical Research telescope.

The telescope is a partnership among UNC, the U.S. National Optical Astronomy Observatory, the Ministry of Science of Brazil and Michigan State University.

An infrared instrument, which allows the telescope to detect remnants of the gamma burst, had been installed just a week before the discovery.

Within hours after the SOAR observation, the UNC research team set out to assess the incoming information.

By happenstance, junior Josh Haislip was the first to analyze the data from SOAR.

Many of Reichart's graduate students were in Greece attending a conference, and Haislip filled in for them.

"Josh was next in line," Reichart said. "So I asked him to read the manual, to prepare just in case anything exciting happened."

Haislip will be the first author on the upcoming research publication. The other UNC students who aided in the discovery are graduate student Melissa Nysewander, and seniors Justin Kirschbrown and Chelsea MacLeod.

 

Contact the University Editor at udesk@unc.edu.