This Echo is READ ONLY !   NO Un-Authorized Messages Please!
 ~~~~~~~~~~~~~~~~~~~~~~~~   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

sci.esa.int
ESA Science News 

A gamma-ray burst bonanza

24 Mar 2003 

ESA's Integral satellite is detecting gamma-ray bursts at a rate of
nearly one per day, establishing itself as a key player in the hunt
for these enigmatic explosions.

Launched in October 2002, Integral has just captured four bursts in
the last four months right in the middle of its field of view. Such
precision observations are providing scientists with a remarkable
view of gamma-ray bursts, which occur randomly, fade within seconds,
and yet shine with the intensity of millions upon millions of Suns.

"We made Integral to study supernovae, black holes, and neutron
stars, yet already we see how this versatile satellite can contribute
greatly to the field of gamma-ray bursts," says Chris Winkler,
Integral Project Scientist.

Gamma-ray bursts are distant explosions of unknown origin. Scientists
say that these bursts signal the birth of a brand new black hole,
either through the death of a massive star or through the merger of
two neutron stars or black holes. The bursts fade within seconds,
never to appear in the same place twice, so scientists have been
hard-pressed to study the bursts in detail.

Integral, with its four main instruments, helps locate bursts for
follow-up study in two primary ways. The anti-coincidence system of
one of its instruments (which usually helps eliminate background
noise) can detect a gamma-ray burst almost anywhere in the sky and
does so about every day.

Integral shares this information with other gamma-ray detectors that
comprise the Interplanetary Network. Together, these simple
detectors, which are located on spacecraft across the Solar System,
pinpoint the location of a burst through triangulation. The process
takes a little time, but within a few days, scientists have enough
information to find the gamma-ray burst afterglow and study it.

About once a month, however, a gamma-ray burst goes off within
Integral's field of view. Integral has detected four bursts this way
dead on. The most recent burst (GRB 030227) triggered very many
follow-up observations. Integral can provide a unique perspective for
those gamma-ray bursts caught directly in its field of view because
it can view the bursts rapidly with four instruments. These
instruments are an imager, a spectrometer, an X-ray monitor, and an
optical camera. All of them observe the same region of the sky
simultaneously.

The Integral team expects the satellite's capability for detecting,
locating, and relaying information about gamma-ray bursts will
improve markedly in the coming months.

Integral team members discuss their gamma-ray burst findings so far
in a press conference on 24 March 2003 at a meeting of the High
Energy Astrophysics Division of the American Astronomical Society at
Mt. Tremblant, Quebec, Canada.

 - END OF FILE -
==========

@Message posted automagically by IMTHINGS POST 1.30
---