The Study Of γ-ray Burst Fireball Model

In this paper, I mainly introduce the GRB(Gamma-ray bursts) fireball-model with a pulsar at the center and the GRB fireball-model including the effect of synchrotron self-absorption on the basis of the standard GRB fire-model.GRBs which are the short and intense bursts of IGOKeV-lMeV photons have puzzled astronomers since their accidental discovery in the late sixties. The afterglow from some GRBs observed by the Italian/Dutch satellite BeppoSAX has strong confirmed the cosmological origin. I review the latest research summarily, including the specialities of GRB, afterglow observations, fireball model and energy progenitor mechanism .The GRB fireball model with a millisecond pulsar at the center is discussed carefully. I modify the energy conservation equation provided by the previous. The radiation flux of two gamma-ray bursts (GRB970228 and GRB000301) afterglows has been studied using the fireball model with a millisecond pulsar at the center, which turns out to be well consistent with the observation data. Our study also explains the break of the optical R-band of the light curve of these afterglows, and shows the pulsar parameters have significant effects on the light curve of the afterglows.Then I take into account the effect of synchrotron self-absorption which make . the fireball shell evolve from optical depth to optical thinness at low bands, the radiation spectra and flux of gamma-ray burst afterglow are discussed. And we present GRB970508 afterglow light curve in optical R and Radio bands. Although the light curve seem much more complicated, our results can still present a rather satisfactory agreement with observation. So we suggest that synchrotron self-absorption and inner engine mechanism should" be comprehensively studied either in fireball model in order to make theoretical calculation fit the observed light curve completely well.