Fermi Gamma-ray Space Telescope

K-corrected Prompt Energy Release for Fermi-GBM Gamma Ray Bursts

Corinne Fletcher
(Adam Goldstein, Suraj Poolakkil, Robert Preece)


With the detection of gravitational-wave GW170817 by LIGO and the prompt electromagnetic component GRB 170817A with the Fermi- Gamma-ray Burst Monitor (Fermi-GBM), the study of Gamma-ray Bursts (GRBs) has become a vital area of astrophysics. GRBs are thought to be the result of core collapse supernovae or compact binary mergers. Calculating the rest-frame energetics is key to understanding the central engine and emission physics of the GRB. The redshift is required to determine the energetics in the rest frame of the event and is only known for a fraction of the events. However, of the 2300 GRB spectra obtained with Fermi-GBM over the last 10 years, we know the redshift for 135, providing one of the largest samples of GRB energetics to date. A few spectral models have proven useful in reproducing the spectral shape of these events and determining the fluence from the GRB spectrum, i.e the Band or Comptonized models. Using Fermi-GBM data and these spectral models, we determined the fluence in the GBM bandpass (10 -1000 keV). For those GRBs with known redshift, we present the k-corrected energy of the GRB in the co-moving bolometric bandpass of 1 keV to 1 MeV and the estimated uncertainty on the prompt energy release.