George Mason University

News at Mason

Looking to the skies and the future with the Fermi Space Telescope

July 20, 2018   /   by Mary Lee Clark

The Fermi Gamma-ray Space Telescope. Image courtesy of NASA.

Students never know where their research might lead them. John Kroon’s research at Mason landed him a prestigious job working as a postdoc at the U.S. Naval Research Laboratory. 

Kroon, PhD Physics ’16, works on analytical models to be applied to gamma-ray flares of a supernova remnant called the Crab Nebula. ​

The data Kroon uses comes from a NASA telescope that he was already familiar with as a Mason student while working in collaboration with Peter A. Becker, professor of astrophysical, planetary and space sciences in the Department of Physics and Astronomy in Mason’s College of Science. ​

Since coming to Mason in 1992, Becker has worked with students in analyzing data and publishing the results from multiple telescopes such as the Fermi Gamma-ray Space Telescope and the NuSTAR X-ray telescope. Through these telescopes, scientists can observe radiation emitted by particles with energies far greater than those seen on Earth.​

The source of the gamma-ray data, the Fermi telescope, is a collaboration between NASA, the U.S. Department of Energy and institutions all over the world. The telescope recently celebrated its 10th anniversary of scanning the skies for gamma rays.​

As a student, Kroon helped Becker develop theoretical models and analyze data from the Fermi telescope. Together, they were the first to put together a physical explanation for the spectrum of gamma rays that occur during “flares”—bursts of high-energy light from the pulsar at the center of the Crab Nebula. ​

Their study was published in the Astrophysical Journal, and Becker and his students have also published many other studies together. Kroon said Becker’s ability to show him how to write professional-grade manuscripts for publication in peer-reviewed journals has helped him succeed in his current position.  ​

“His several research collaborations have led to successful professional pursuits after graduate studies and, in my case, has landed me at the forefront of high-energy astrophysical research,” said Kroon. ​

Tyrel Johnson, a research associate professor at Mason, also works with the Fermi telescope in a different capacity. He started with the project two years before the telescope was launched as part of a group of scientists that worked to put the telescope in space. Now, he runs calibrations and analyzes the collected data.   

“The Fermi Large Area Telescope is like a video recorder—always on, just scanning the sky,” said Johnson, who interprets the raw data sent to the lab when the telescope detects gamma rays.  

The orbital telescope has led to a new way of looking at the galaxy and has stimulated many fascinating discoveries, including added support for Einstein’s theory that the speed of light is constant for all photon energies. Here at Mason, the university’s partnership with Fermi scientists has provided faculty and students with unique sets of data to pursue their research. 

“The Fermi telescope has provided insight into the most extreme environments in the galaxy, which has shed light on the processes not only taking place all around us, but [also on] forces which have shaped the evolution of the galaxy,” Kroon said.