Gamma-Ray Astrophysics NSSTC Fermi GBM
The Fermi Gamma-Ray Burst Monitor (GBM) is not a pointed or imaging instrument. To determine fluxes for known sources, we measure the change in the count rate observed in the NaI (or BGO) detectors when the source enters or exits Earth occultation. The measured counts in each energy channel are converted to fluxes …