I. W. Kirkman

1000 GeV Gamma Rays from the 1.5 ms Pulsar

The 1.5 ms pulsar PSR1937+21 has been observed using the Dugway 1000 GeV gamma ray telescopes and the observations show evidence for pulsed VHE gamma ray emission, significant at better than the 3.5 sd level. The signal comprises two pulses separated by half the period which is similar to the radio emission. The total energy flux in VHE gamma rays is 2x10 erg s-l and agrees with the prediction of a current model that the peak emission of electromagnetic energy should be near 100 GeV.

Simultaneous Measurements of VHE Gamma Rays from Hercules X-1

We report the results of a measurement of VHE gamma rays from Her X-l made using the Dugway telescopes which coincided with a similar measurement at the Whipple Observatory reported by Gorham (1986). In both observations evidence for emission of VHE gamma rays showing the same periodicity and significant at about the 3 sd level was obtained. This represents the first simultaneous detection of a VHE gamma ray source by two independent telescopes.

The VHE Gamma Ray Light Curve of PSR0531

Measurements of the light curve of the Crab pulsar at TeV energies indicate a very narrow feature coincident with the radio main pulse with little evidence for an interpulse. This result is compared with the predictions of the pulsar model of Cheng, Ho and Ruderman.