A Compact Fireball Model of Gamma Ray Bursts

It is proposed that the gamma ray burst photons near the peak of the spectrum at several hundred KeV are thermal. This would constrain the emission to come from radii much smaller than in models that invoke emission from an optically thin region. It is argued that the fast variations of order milliseconds in the time profile is a natural expectation, given the other observed GRB parameters. Analytic calculations are presented to show that the escape of non-thermal, energetic gamma rays can emerge within a second of the thermal photons from a gammasphere of below 10 cm.