Compton dragged gamma–ray bursts: the spectrum

We calculate the spectrum resulting from the interaction of a fireball with ambient soft photons. These photons are assumed to be produced by the walls of a funnel in a massive star. By parameterizing the radial dependence of the funnel temperature we calculate the deceleration of the fireball self–consistently, taking into account the absorption of high energy γ–rays due to interaction with the softer ambient photons. The resulting spectrum is peaked at energies in agreement with observations, has a ν slope in the X–ray band and a steep power–law high energy tail.