NASA scientists designing new instrument to detect the most powerful blasts in the universe

June 18, 2000

Astronomers said a fond farewell to NASA's Compton Gamma Ray Observatory earlier this month. The Compton Observatory was instrumental in proving gamma-ray bursts come from the most distant reaches of the cosmos and are the most powerful explosions in the universe.

A team led by scientists at NASA's Marshall Space Flight Center in Huntsville, Ala., is developing a new burst monitor to fly on Compton's successor -- the Gamma Ray Large Area Space Telescope, or GLAST -- planned for launch in 2005.

The GLAST Burst Monitor -- working with GLAST's main instrument, the Large Area Telescope -- will provide the broadest energy coverage ever available on a single spacecraft for gamma-ray studies. Together, the two instruments will observe gamma rays with the lowest energies to those with the highest energies.

"We want to discover how these bursts light up the universe with such a tremendous amount of energy," said Dr. Charles Meegan, a Marshall Center astrophysicist and the principal investigator for the project. "We want to determine the nature of gamma-ray bursts -- still one of the greatest mysteries of astrophysics."

To design the new instrument, Marshall Center scientists will draw on more than two decades of experience building and operating the Burst and Transient Source Experiment -- also known as BATSE -- one of four instruments on the Compton Observatory. During its productive nine-year life, BATSE observed more than 2,500 gamma-ray bursts, but astronomers are still puzzled about the nature of these illusive objects.

"The total amount of energy emitted by all the stars in our galaxy is not as much energy as that released by one gamma-ray burst in a few seconds," said Meegan. "In 10 seconds, a gamma-ray burst can discharge thousands of times more energy than our Sun will ever give off in its entire lifetime. Scientists have had trouble figuring out just what could cause such violent blasts coming from all parts of the universe."

Meegan, who enjoys working all types of puzzles, is eager to lead a team to build an instrument capable of solving the mystery surrounding gamma-ray bursts. Many questions remain for the team to investigate.

What is the source of explosions emitting most of their energy in gamma rays - the highest energy radiation, even more powerful than X-rays? How are the explosions created? Have these blasts influenced Earth over the course of the planet's history?

"To find out what is causing these explosions, we will use the GLAST Burst Monitor to observe most of the energy released by a burst, while the primary telescope detects the very highest energy gamma rays emitted during the blast," said Meegan.

When a burst occurs, the GLAST Burst Monitor will detect gamma rays from the burst and identify the location of the burst quickly. Then, computers will use this information to automatically point the Large Area Telescope toward the burst.

Working in concert, the GLAST instruments will see energy from a few thousand electron volts to billions of electron volts. By recording over an energy range hundreds of times larger than that detected by BATSE, astronomers may come closer to finding out what causes these explosions.

Are the explosions the birth announcement of a black hole -- a collapsed star with gravity so strong that it devours other objects and not even light can escape?

Or are they the death of a neutron star -- a tiny star made of material so heavy that a sugar cube-sized piece can weigh as much as a billion tons? Scientists don't know.

"We are witnessing something dramatic in the life of an astronomical object," said Meegan. "Our experience with BATSE showed us that if you try to predict what it is without data, you'll be wrong. If bursts have done any thing, they have made scientists humble."

To design the best instrument, Meegan has assembled a team that includes scientists from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, who are collaborating with NASA through an agreement with the German Space Agency. The Max Planck Institute will build crystal detectors -- the monitor's main component for intercepting gamma rays. Scientists from the Marshall Center and the University of Alabama in Huntsville will provide the flight electronics and software for the instrument.

The project also will be an opportunity for the next generation of gamma-ray astronomers to learn how to build a major scientific instrument. The team includes many young astronomers -- who began their careers by analyzing BATSE data -- from the Marshall Center and the University of Alabama in Huntsville.
-end-
Goddard Space Flight Center in Greenbelt, Md., will manage the GLAST mission for NASA's Office of Space Science in Washington, D.C.




NASA/Marshall Space Flight Center News Center

Related Gamma Rays Articles from Brightsurf:

Properties of catalysts studied with gamma ray resonance
Steam-assisted oil extraction methods for heavy deposits have long been the focus of attention at Kazan Federal University.

Strange gamma-ray heartbeat puzzles scientists
Scientists have detected a mysterious gamma-ray heartbeat coming from a cosmic gas cloud.

Physicists find ways to control gamma radiation
Researchers from Kazan Federal University, Texas A&M University and Institute of Applied Physics (Russian Academy of Sciences) found ways to direct high frequency gamma radiation by means of acoustics.

Excess neutrinos and missing gamma rays?
A new model points to the coronoe of supermassive black holes at the cores of active galaxies to help explain the excess neutrinos observed by the IceCube Neutrino Observatory.

APS tip sheet: correlating matter's distribution in the universe with gamma rays
Scientists present the first direct cross-correlation between dark matter and gamma ray emissions.

APS tip sheet: High energy gamma rays
Nine Galactic sources are the highest-energy gamma -ray sources ever detected, which could suggest the presence of Galactic accelerators.

First detection of gamma-ray burst afterglow in very-high-energy gamma light
An international team of researchers observe a gamma-ray burst, an extremely energetic flash following a cosmological cataclysm, emitting very-high-energy gamma-rays long after the initial explosion.

Gamma-ray bursts with record energy
The strongest explosions in the universe produce even more energetic radiation than previously known: Using specialised telescopes, two international teams have registered the highest energy gamma rays ever measured from so-called gamma-ray bursts, reaching about 100 billion times as much energy as visible light.

Hubble studies gamma-ray burst with highest energy ever seen
NASA's Hubble Space Telescope has given astronomers a peek at the location of the most energetic outburst ever seen in the universe -- a blast of gamma-rays a trillion times more powerful than visible light.

The highest energy gamma rays discovered by the Tibet ASgamma experiment
The Tibet ASgamma experiment, a China-Japan joint research project, has discovered the highest energy cosmic gamma rays ever observed from an astrophysical source - in this case, the 'Crab Nebula.' The experiment detected gamma rays ranging from > 100 Teraelectron volts (TeV) to an estimated 450 TeV.

Read More: Gamma Rays News and Gamma Rays Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.