Gamma-Ray Burst Monitor

Gamma-RayThe Fermi Gamma-ray Space Telescope, formerly GLAST, was launched on June 11, 2008.

Fermi instruments, the Gamma-Ray Burst Monitor (GBM).CSPAR scientists are part of the team that designed, built and operate one of the two Fermi instruments, the Gamma-Ray Burst Monitor (GBM).

The primary objective of GBMis to extend the energy range over which gamma-ray bursts (GRBs) are observed downward from the energy range of the Large Area Telescope (LAT) on Fermi into the hard X-ray range where extensive previous data sets exist. A secondary objective is to compute GRB locations on-board to allow re-orienting the spacecraft so that the LAT can observe delayed emission from bright bursts. GBM uses an array of twelve sodium iodide (NaI) scintillators and two bismuth germanate (BGO) scintillators to detect gamma rays from ~8 keV to ~40 MeV over the full unocculted sky.

Software on-board GBM detects and localizes GRBs and transmits information to the LAT and to the ground in near real time. GBM also triggers on solar flares, Terrestrial Gamma Flashes (TGFs) and Soft Gamma Repeaters (SGRs), allowing detailed studies of these sources. When not processing a burst trigger, GBM transmits background data useful for monitoring various astrophysical X-ray sources, most notably X-ray pulsars and microquasars.