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A-2 LED Soft X-ray Sky Catalog


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


This data set consists of EBCDIC magnetic tape containing the HEAO A-2 low-energy X-ray source catalog as published in the Astrophysical Journal Supplement Series. Some 95% of the sky was surveyed in the spectral bands 0.18 to 0.44 and 0.44 to 2.8 keV to limiting sensitivities of 1E-11 and 3E-11 ergs/(sq cm s), respectively. The catalog lists 114 sources to a six-sigma significance criterion. The data are arranged in the form of pages in the published catalog where each record, containing 132 bytes, represents a line in the catalog, and each source listing consists of six lines. Source positions are given in galactic coordinates as well as in RA and Dec. Measured intensity is expressed in counts/s. For further details see Nugent et al., Astrophys. J. Suppl., v. 51, p. 1, 1983.

Alternate Names


    • Astronomy: X-Ray


    • 77-075A-02F

    Additional Information



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



    NameRoleOriginal AffiliationE-mail
    Dr. John A. NousekData ProviderPennsylvania State

    Selected References

    • Nugent, J. J., et al., HEAO A-2 soft X-ray source catalog, Astrophys. J. Suppl. Ser., 51, 1-28, doi:10.1086/190838, Jan. 1983.
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