On the ultrahigh-energy gamma rays from Cygnus X-3 Academic Article uri icon


  • The way in which the generation of ultrahigh-energy (UHE) gamma rays can be incorporated into a model of the Cyg X-3 system as a young pulsar in a close binary system is examined. It is shown that the observed UHE light curve can be naturally reproduced if the companion's atmosphere acts as target material for particles accelerated near the pulsar. Clues the UHE radiation provides about the mechanisms of particle acceleration are examined, and it is concluded that particles are probably accelerated with very high efficiency. Geometric considerations suggest that they are accelerated by a pulsar. Future UHE observations may rule out shock-accelerated electrons and protons (of any origin) as progenitors of the UHE radiation, thereby giving further evidence that these primaries are e(+)/e(-) pairs originating from the pulsar. Detailed UHE observations may thus provide relatively direct measurements of the energy spectrum, and type of relativistic particles emitted by a pulsar. The possible existence of other objects, not yet discovered, that are similar to Cyg X-3 is discussed.

publication date

  • January 1, 1982