γ Rays of 0.3-30 MeV from PSR0833-45

Pulsed γ rays from the Vela pulsar PSR0833-45 are reported here for the first time at the medium energies, E, of 0.3-30 MeV. They were observed with the University of California, Riverside double scatter γ-ray telescope¹ flown on a balloon from Alice Springs, Australia, on 10 November 1981, 31 days after a large glitch in the pulsar period. The first and second pulses were detected from single scatters in the top scintillators, S1, at energies >0.3 MeV with statistical significances of 1.6σ and 1.6σ (together 2σ), and hy double scatters from all detector cell pairs at energies of 1-30 MeV with significances of 4.8σ and 3.8σ (together 5.8σ). The phase separation of the two pulses is 0.43+/-0.02 at the same absolute phases previously found by SAS 2 ² and COS B ³ for E>35 MeV. The energy distribution with six points from 0.3 to 30 MeV appears to bend away from the COS B power law⁴ at the lower energies and is well below the HEAO 1 ⁵ upper limits.