A comment on the very high (>= 1015 eV) gamma ray from Cyg X-3 based on the data of Akeno Observatory

Gamma ray data from Cyg X-3 observed at Akeno Observatory for more than three years since early 1981 were analyzed and main results are briefly presented here. Periodic changes were compared with those of X-ray (period 4.8 hours) observed and reported by Parsignault et al. or by Van der Klis and Bonnet-Bidault. The coincidence of periods of both gamma ray and X ray was tested by the method of harmonic analysis and was proved not to be an accidental coincidence. A statistically meaningful correlation with fluctuation of X-ray from Cyg X-3 is observed only in the direction of Cyg X-3. This suggests existence of some physical meaning. Other analyses including gamma ray absolute flux, shower age, and lateral distribution of muon are now underway. (Aoki, K.)