Spectral-Temporal Simulations of Internal Dissipation Models of Gamma-Ray Bursts

Understand

We present calculations of the time evolution of the prompt spectra of gamma-ray burst models involving generic internal dissipation regions, including internal shocks, either by itself or in the presence of an external photon source such as a photosphere.

• The method uses a newly developed time-dependent code involving synchrotron emission and absorption, inverse Compton scattering and pair formation.
• The models reproduce the typical observed Band spectra and their generic time evolution, including the appearance of an extra keV-GeV component, whose delay in simple SSC models, however, is only partially able to explain the several seconds observed GeV delays.
• On the other hand, models involving both a photosphere and an internal dissipation region at a larger radius produce both an extra GeV component and time delays which are in the range of the observations.