NASA telescope sees most extreme gamma-ray blast yet

February 20th, 2009 - 3:27 pm ICT by ANI  

Washington, Feb 20 (ANI): NASAs Fermi Telescope has detected the most extreme gamma-ray blast in history, which has been seen in high resolution.

The blast had the greatest total energy, the fastest motions and the highest-energy initial emissions ever seen.

We were waiting for this one, said Peter Michelson, the principal investigator on Fermis Large Area Telescope at Stanford University. Burst emissions at these energies are still poorly understood, and Fermi is giving us the tools to understand them, he added.

Gamma-ray bursts are the universes most luminous explosions. Astronomers believe most occur when exotic massive stars run out of nuclear fuel.

As a stars core collapses into a black hole, jets of material - powered by processes not yet fully understood - blast outward at nearly the speed of light.

The jets bore all the way through the collapsing star and continue into space, where they interact with gas previously shed by the star and generate bright afterglows that fade with time.

This explosion, designated GRB 080916C, occurred on September 15, in the constellation Carina.

Fermis other instrument, the Gamma-ray Burst Monitor, simultaneously recorded the event.

Together, the two instruments provide a view of the blasts initial, or prompt, gamma-ray emission from energies between 3,000 to more than 5 billion times that of visible light.

Nearly 32 hours after the blast, Jochen Greiner of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, led a group that searched for the explosions fading afterglow.

The team simultaneously captured the field in seven wavelengths using the Gamma-Ray Burst Optical/Near-Infrared Detector, or GROND, on the 2.2-meter telescope at the European Southern Observatory in La Silla, Chile.

In certain colors, the brightness of a distant object shows a characteristic drop-off caused by intervening gas clouds.

The farther away the object is, the redder the wavelength where this fade-out occurs. This gives astronomers a quick estimate of the objects distance.

The teams follow-up observations established that the explosion took place 12.2 billion light-years away.

Already, this was an exciting burst, said Julie McEnery, a Fermi deputy project scientist at NASAs Goddard Space Flight Center in Greenbelt, Maryland. But, with the GROND teams distance, it went from exciting to extraordinary, she added.

With the distance in hand, Fermi team members showed that the blast exceeded the power of approximately 9,000 ordinary supernovae, if the energy was emitted equally in all directions. (ANI)

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