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Possible γ-ray line from the Crab Nebula

Naturevolume 266pages696698 (1977) | Download Citation



A BALLOON-BORNE γ-ray telescope was flown on 10–11 May 1976 from Alamogordo, New Mexico to search for celestial γ-ray lines in the energy range 100 keV–5.0 MeV. We report here evidence for a line feature from the Crab Nebula at 400±1 keV. Although the counting statistics do not allow us to make an incontestible claim, the fact that it occurs at a reasonable energy to be gravitationally redshifted positron annihilation radiation occurring at the surface of the Crab Pulsar, and in all respects seems to be a real astronomical line, has encouraged us to bring this to the attention of the astronomical community.

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  1. Bell Laboratories, Murray Hill, New Jersey, 07974

  2. Sandia Laboratories, Albuquerque, New Mexico, 87115

    •  & A. C. WATTS


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