Prospects of observing pulsed radiation from gamma-ray pulsars with H.E.S.S

Observations and theoretical studies have demonstrated that the pulsed spectra of all gamma-ray pulsars terminate at energies below a few hundred GeV. In most cases we expect this cutoff energy Eo to be around 10 GeV. Only with next-generation ground-based γ-ray telescopes, which are expected to have non-zero trigger probabilities near 10 GeV, can we expect to detect pulsations. The large γ-ray fluxes below Eo, together with the associated sharp pulse profiles, compensate for the lack of imaging capability near threshold. For H.E.S.S. we find that the pulsed component of PSR B1706-44 should be detectable near threshold, whereas the unidentified GeV EGRET sources should be detectable if the superexponential cutoff energy is larger than ∼30 GeV for relatively hard pulsar photon spectra (∼E-1.5)