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A timing analysis of VHE gamma-ray observations of Cen X-3 taken with theUniversity of Durham Mark 6 telescope was performed, using both Rayleigh andBayesian statistics. Data from only 1 observation produced evidence forperiodicity, in a 'soft' cut data set, with an overall chance probability <0.01and blueshifted by 6.6ms from the nominal second harmonic of the pulse period.We show that the disappearance of the Rayleigh peak in the fully cut data setis consistent with a gamma-ray origin hypothesis. The second part of the paperconsiders theoretical models that could explain the existing data of Cen X-3 inhigh and very high energy gamma-rays. On the basis of energetics, allreasonable options for gamma-ray production must be connected to jets emergingfrom the inner accretion disc around the neutron star. One principal option isa large scale source, with R_s~10^13-14cm, assuming effective acceleration ofelectrons by shocks produced by the interaction of the jets with the denseatmosphere of the binary. The bulk of gamma-ray features could be explained bythis model except modulations at the pulsar period, which would require asource with R_s<10^11cm. We consider hadronic and leptonic models for theformation of such a compact object. Both models predict the episodes of pulsedemission may be rare, of typical duration ~few hours, and the frequency ofpulsations should be significantly shifted from the nominal frequency of theX-ray pulsar. The opportunities to distinguish between different models usingfuture gamma-ray observations of this X-ray binary are discussed. (v. abridged)Comment: 18 pages, 10 figures to be published in Astronomy and Astrophysic

Very high energy gamma-rays from Centaurus X-3: Indications and implications