On the spectra of gamma-ray bursts

Summary One of the possible interpretations of the spectra of gammaray bursts is in terms of synchrotron emissivity of mildly relativistic electrons. In this case, the shape of the spectra depends on the angle between the magnetic field and the observer. We show here that, although this angle can be important for single events, the statistical properties of gamma-ray bursts are determined essentially by those events for which this angle is near π/2, namely events observed in the direction of maximum emitted flux. Paper presented at the 2° Convegno Nazionale di Fisica Cosmica, held at L'Aquila, 29 May–2 June 1984.