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Skymap Display Files


Availability: At NSSDC, Ready for Offline Distribution (or Staging if Digital)

Time span: 1977-08-21 to 1979-01-08


This data set was obtained from the Low Energy Detectors (LEDs) of the Hard X-ray and Low-Energy Gamma-ray Instrument. The data, which were all obtained when the satellite was spinning, consist of event counts and detector lifetimes for four broad energy channels for each of the two LEDs, and have been accumulated as a function of satellite orientation. The skymap display files contain background subtracted count rates that are used to construct visual displays. Each file contains roughly 6 months of data. The files with epoch code 1 cover the first 6 months of the mission; epoch code 2 stands for the second 6 months and epoch code 3 stands for the remainder, i.e., about 5 months, of the mission. The epoch "T" stands for the total and indicates that the data are the superposition of data from all three epochs. The count rate data in the skymap display files have been smoothed so as to reduce the high frequency spatial noise. The lifetime data in the exposure files have been left unsmoothed. This data set consists of binary magnetic tape covering the time span August 21, 1977, to January 8, 1979. The multifiled tapes were created on a Data General Nova 830 computer. For additional information, contact Dr. Duane E. Gruber, C-011, Center for Astrophysics and Space Astronomy, University of California-San Diego, La Jolla, CA 92093.

Alternate Names


    • Astronomy: Gamma Ray


    • 77-075A-04B

    Additional Information



    Questions and comments about this data collection can be directed to: Coordinated Request and User Support Office



    NameRoleOriginal AffiliationE-mail
    Dr. Alan M. LevineData ProviderMassachusetts Institute of
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