Transient Gamma-Ray Spectrometer (TGRS) on WIND

The main purpose of the Wind spacecraft is to measure the incoming
solar wind, magnetic fields and particles, although early on it will
also observe the Earth's foreshock region. Wind, together with
Geotail, Polar, SOHO, and Cluster projects, constitute a cooperative
scientific satellite project designated the International Solar
Terrestrial Physics (ISTP) program which aims at gaining improved
understanding of the physics of solar terrestrial relations.

The Transient Gamma-Ray Spectrometer (TGRS) aboard the WIND spacecraft
is designed to perform spectroscopy of both transient and steady
sources in the hard X-ray and gamma-ray region (~20-8000 keV). There
are several line-forming physical processes in this region that make
it particularly interesting for spectroscopy, such as particle
acceleration, interaction, and confinement, cyclotron, annihilation
and nuclear processes. The more energetic events in the sky are
usually responsible, such as supernovae, neutron stars, and material
falling into black holes. Astrophysical sources studied and monitored
by TGRS include gamma-ray bursts (GRBs), solar flares, bright galactic
transient sources like the recently discovered GRO J1655-40, and
steady sources like the Crab and the Galactic Center. TGRS with its
high resolution and moderate sensitivity, and KONUS (the other
gamma-ray instrument on WIND) with its high sensitivity but lesser
resolution ideally complement each other in these observations.

The main objective of TGRS is to perform high resolution measurements
of GRB spectra and time histories, with particular emphasis on the
search for line features in the energy spectra. As part of an
interplanetary network of spacecrafts, KONUS is currently supporting
the extremely important deep search for quiescent GRB counterparts in
other wavelengths by contributing to the determination of accurate GRB
locations from multi-spacecraft timing.

Data is available at the NSSDC CDAWeb
(http://cdaweb.gsfc.nasa.gov/cdaweb/)