ULTRAVIOLET BACKGROUND-RADIATION

We have reanalyzed the UVX measurements of the surface brightness of the diffuse ultraviolet background above \b\ = 40-degrees using the dust-scattering model of Onaka & Kodaira (1991), which explicitly takes into account the variation of the source function with galactic longitude. The range of allowed values of interstellar grain albedo a, and scattering asymmetry parameter g, is considerably expanded over those of a previous analysis. The new chi2 probability contours come close to, but do not include, the values of a and g found for the interstellar grains by Witt et al. (1992) using the Ultraviolet Imaging Telescope on the Astro-1 mission. If we hypothesize in addition to the dust-scattered light an extragalactic component of 300 +/- 100 photons cm-2 s-1 sr-1 angstrom-1, attenuated by a cosecant b law, the new reduction of the UVX data gives complete consistency with the Witt et al. determination of the optical parameters of the grains in the ultraviolet.