Summary

Measurement of T90 durations as a function of energy for a set of bright gamma-ray bursts detected by the Fermi Gamma-Ray Burst Monitor above 500 keV in 2008-2009

Description

We have a sample of 50 bright gamma-ray bursts (GRBs) observed with the Fermi Gamma-ray Burst Monitor (GBM) at energies >500 keV. The sample was initially selected from the set of 253 GBM GRBs collected during the first year of operation (July 2008-July 2009) based on their 64ms peak count rate. The GRB duration (the so-called T90) was already determined at high energy over five energy channels, namely at 300-500 keV, 500 keV-1 MeV, 1-2 MeV, 2-5 MeV, and 5-10 MeV. The student needs to expand the duration calculation at lower energies over four additional intervals: 8-25 keV, 25-50 keV, 50-100 keV, 100-300 keV. Applying a power law fit, the duration-energy relation can thus be studied over an unprecedently broad energy domain, ranging from 8 keV to 10 MeV.