The Double-Peak Spectral Energy Density of Gamma-Ray Bursts and the True Identity of GRB 031203
Abstract
A double-peak spectral energy density of prompt γ-rays, similar to that observed in blazars, is expected in the cannonball (CB) model of gamma-ray bursts (GRBs) produced in supernova (SN) explosions. The first sub-MeV ordinary peak is formed by inverse Compton scattering (ICS) of the ambient SN light by the CBs' electrons, while the second peak at GeV-TeV energies is formed by ICS of interstellar medium electrons accelerated by the jetted CBs from the SN explosion. Usually the second peak is in the GeV-TeV range. However, in X-ray flashes with a low peak energy, which in the CB model are normal GRBs viewed far off-axis, the second peak energy moves to the MeV range. In far off-axis GRBs, such as 980425 and 031203, the second peak may have been confused with the normal GRB peak. In most GRBs that have been observed so far, the γ-ray detectors ran out of statistics far below the second peak. However, in bright GRBs, the two peaks may be resolved by simultaneous measurements with Swift, INTEGRAL, and GLAST.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2005
- DOI:
- 10.1086/432416
- arXiv:
- arXiv:astro-ph/0409466
- Bibcode:
- 2005ApJ...627L.109D
- Keywords:
-
- Gamma Rays: Bursts;
- Stars: Supernovae: General;
- Astrophysics
- E-Print:
- The estimated soft X-ray fluence in GRB 031203 was replaced in the text and Fig. 3 with the correct estimate by Vaughan et al. Corrected typos