Annu. Rev. Astron. Astrophys. 1991. 29: 89-127 Copyright © 1991 by Annual Reviews. All rights reserved

7. FUTURE DIRECTIONS

In the study of diffuse ultraviolet background radiation we need a sophisticated and systematic effort to spatially and spectrally map the entire sky. Just such an effort has been proposed by Kimble, Henry & Paresce (57).

Their proposed instrumentation offers not only unprecedented sensitivity, spectral resolution, and all the other good things, but also unprecedented attention to the sources of concern that I have described above. The proposed experiment has the defect of being confined to wavelengths longward of 1216 Å, but that seems to be where the signal is, and in any case, it is a defect of caution, as they do not wish to use a windowless detector nor do they wish to admit L.

A sounding-rocket experiment to confirm the Voyager upper limit shortward of L would be of the very greatest value. In this review I depended on data from Voyager; and it would be important to see independent confirmation of those crucial upper limits. The experiment could use a very wide field of view, as the surface brightness due to all known stars at 1100 Å, at high galactic latitudes, is much less than 100 units.

ACKNOWLEDGMENTS

I am grateful to all of my collaborators and supporters over the years, particularly Paul D. Feldman and William G. Fastie. Partial support for this work came from NASA grants NAG5-619 and NAGW-1890 to The Johns Hopkins University, and from the SDIO Backgrounds Data Center, US Naval Research Laboratory.