Epeak Estimator For Gamma-ray Bursts Observed By Swift BAT
Abstract
We report a correlation based on the spectral simulation study in the prompt emission spectrum of gamma-ray bursts (GRBs). The correlation is between the photon index derived from a simple
power-law model by the Swift Burst Alert Telescope (BAT) and the Epeak energy, which is the peak energy in the nuF_nu spectrum. We take into account not only the various range of Epeak energies and fluences, but also distributions for both the low-energy photon index and the high-energy photon index in the smoothly broken power-law model. Our correlation is consistent with the photon index observed by BAT and Epeak measured by BAT and other GRB instruments. Since about 80% of GRBs observed by BAT are acceptably fit with the simple power-law model because of the relatively narrow energy range of BAT, this relationship can be used to estimate Epeak for most of the Swift GRBs.- Publication:
-
AAS/High Energy Astrophysics Division #9
- Pub Date:
- September 2006
- Bibcode:
- 2006HEAD....9.1704S