Implications of 10¹⁶ eV γ rays from Cyg X-3

Samorski and Stamm¹ have reported and Lloyd-Evans et al. ² have recently confirmed the detection of high-energy quanta, presumably γ rays, with energies E>2×10¹⁵ eV from Cygnus X-3. These ultra-high energy (UHE) γ rays were detected with extensive air shower arrays and included four events with E>10¹⁶ eV. Temporal analyses^1,2 of the events indicate that the flux is modulated with a 4.8-h period and is sharply pulsed. Here (1) we discuss the implications of these γ-ray detections and suggest that autocorrelating the air shower data may be the best way to determine the intrinsic width of the γ-ray pulses; (2) we argue that the radiating particles are accelerated by a pulsar and that if they are accelerated according to any pulsar mechanism we know of, then they must be ions; (3) we note that if the ions are accelerated to 10¹⁶ eV by a large amplitude Deutsch wave, then the gravitational wave luminosity L_g should exceed that of the Crab pulsar by a factor of ∼5×10⁵, and the spin-down time should be ∼80 yr (requiring a truly remarkable object); and (4) we show that the ions can be accelerated in the near zone but only if, contrary to the standard view, pair production does not greatly reduce the vacuum potential drop in the near zone. We note that near-zone acceleration could be confirmed by detection of curvature radiation.