NASA's novel instrument would help shed new light on gamma ray bursts

Washington, June 1 : Scientists at a US university has helped in designing a new NASA instrument which would help astrophysicists learn more about cosmic explosions that create gamma ray bursts.

Gamma ray bursts are flashes of the most powerful energy in the electromagnetic spectrum - stronger than X-rays and at least 1,000 times as powerful as visible light.

This cosmic phenomenon would be studied by NASA's new GLAST (Gamma-ray Large Area Space Telescope) Burst Monitor, an instrument scheduled to be rocketed into orbit next month.

It was designed by scientists at UA Huntsville (UAH) in Alabama, US, who teamed with NASA's Marshall Space Flight Center and the Max Planck Institute for Extraterrestrial Physics in Germany in proposing and developing the burst monitor, which is a secondary instrument on board NASA's GLAST.

"The UAH contingent is responsible for most of the software, as well as much of the calibration testing and system integration," said Dr. Bill Paciesas, a UA Huntsville physics research professor and the GRM ground system manager.

Paciesas and the UAH team are veterans of the group that developed and operated the Burst and Transient Source Experiment (BATSE) that flew aboard the Compton Gamma Ray Observatory.

One of the unanswered questions for BATSE was whether the sources of the gamma ray bursts were "local" or out of the fringes of the universe.

"BATSE proved that (gamma ray burst sources) are some of the most distant objects we can see in the universe," said Paciesas.

When other telescopes look at the sky where the bursts come from they see evidence of rapidly-dimming explosions or stars often billions of light years from Earth, meaning the events the orbiting detectors record happened billions of years ago when the universe was much younger.

One of the problems with the theories about gamma rays is the fact that because they have such small wavelengths, they are easily blocked.

Earth's atmosphere stops most incoming gamma rays from reaching the ground, which is why gamma ray detectors have to be above the atmosphere.

The question then emerges that if gamma rays are so easily blocked, how do bursts of them escape from events as inherently messy as star collisions?

According to Paciessas, "While the X-ray, ultraviolet and optical after glows of these events can often be tracked for weeks as they fade away, there are many things we don't understand about the mechanism that produces these early gamma rays."

NASA's new GLAST instrument would help answer all these questions.

GLAST is scheduled for launch no earlier than June 3 atop a Delta II Heavy launch vehicle built in Decatur, Alabama.

ANI