BEAM MEETS TARGET - A MODEL FOR EPISODIC GAMMA-RAY SOURCES

For an explanation of the TeV gamma-ray episodes with duration less th an or equal to 1 h observed from the X-ray binaries, we have suggested a model assuming that the beam of relativistic particles accelerated by the compact object meets the massive gas cloud ejected from the nor mal companion star. Here we present the time evolution of the resultin g gamma-ray spectra. We also discuss the possible application of the ' beam-meets-target' model to the GRB, in particular those detected by E GRET, assuming that the accelerator is an isolated pulsar, and the tar get is a comet or asteroid.