TCU astrophysics team helps map the universe

Secrets of the night sky

By Kathryn Hopper, TCU Magazine

Using a high-powered telescope perched on a New Mexican mountaintop, TCU researchers are taking a close-up look at distant stars.

They are part of the Apache Point Observatory Galactic Evolution Experiment (APOGEE), a survey aimed at better understanding thousands of red giant stars in the Milky Way Galaxy.

“We’re studying the chemistry of stars,” says Peter Frinchaboy, assistant professor of physics and astronomy. “Our goal (for APOGEE) is to get the chemistry of 100,000 stars by the middle of 2014, to be able to understand the formation and evolution of our own galaxy and how that ties into other galaxies.”

Frinchaboy made it a priority for TCU to join the Sloan Digital Sky Survey, which includes the APOGEE project, a collaborative effort of more than 300 scientists from universities and research institutes around the world. The Sloan Digital Sky Survey is an ongoing, comprehensive survey of the universe that is searching for extra-solar planets, exploring galaxy formation and evolution, dark mater and dark energy.

Frinchaboy is a leader of the APOGEE project, which is studying infrared properties and chemistry of stars and allows researchers access to many parts of the Milky Way Galaxy that have never been visible in this capacity and clarity.

In June, Frinchaboy and graduate students Ben Thompson and Julia O’Connell traveled to Sunspot, N.M., home of the Apache Point Observatory, where they got a the chance to collect data from the Sloan Foundation 2.5-meter telescope.

It has four spectrographs, which separate incoming into a spectrum, like a prism, that are fed by optical fibers that measure spectra (distances and velocities) of up to a thousand stars, galaxies or distant star-like objects called quasars in a single observation. A custom-designed set of software pipelines keeps pace with the enormous data flow from the telescope.

“APOGEE has one fiber for each object we want to observe,” Frinchaboy said. “We have 300 fibers so we can collect information on 300 different objects at a time. We can collect information on a few thousand targets a night, depending on the season. We can get more in the winter than the summer because of the length of the night.”

The telescope is housed in a building outfitted with rails that move the structure away at sunrise and sunset, exposing the telescope to the night sky.

“The telescope sits on a rotator plate that spins around depending on where we want to look in the sky,” said graduate student O’Connell.

Frinchaboy says the project provides world-class, hands-on research opportunities for both graduate and undergraduate students. The observatory is operated by New Mexico State University and owned by the Astrophysical Research Consortium, which includes top universities such as the University of Chicago, Princeton University, Johns Hopkins University and the University of Virginia.

Frinchaboy says being part of the Sloan survey was a great step and hopes TCU will be able to build on the opportunity.

“TCU is part of this collaboration, which will run through 2014, and we’re already making plans to extend the collaboration through 2020 and possibly be expanded to the Southern Hemisphere as well, so we can get the entire galaxy,” he said.

Thompson, now in his second year of graduate study, was excited to be part of such a prestigious project.

“By mapping out the galaxy, we can tell distances, we can tell how fast the stars are moving and we can tell what they are made of,” he said. “By doing that, we can map the evolution of the galaxy, how it got built up, where stars were formed, where they migrated from. That’s the end goal, to determine how the Milky Way was born.”

When they weren’t collecting data and working with staff to coordinate operations at the observatory, the TCU team passed the time looking for horned frogs — the scaly variety that are native to the New Mexico and still relatively plentiful in the sparsely populated ponderosa forest.

Frinchaboy said they managed to catch one frog who begrudgingly posed for a few photos.

“He looked a little irritated with us, but he let us get a few shots before he scurried away,” Frinchaboy added. Click here to watch the video version of this story.